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Sample records for local anesthetic concentration

  1. Do the Concentration and Volume of Local Anesthetics Affect the Onset and Success of Infraclavicular Anesthesia?

    PubMed Central

    Mosaffa, Faramarz; Gharaei, Babak; Qoreishi, Mohammad; Razavi, Sajjad; Safari, Farhad; Fathi, Mohammad; Mohseni, Gholamreza; Elyasi, Hedayatollah; Hosseini, Fahimeh

    2015-01-01

    Background: Although local anesthesia is a suitable method for upper limb surgeries, there is debate regarding the effects of appropriate dosing. Objectives: In the current study, we investigated the effects of the concentration and volume of a local anesthetic on the beginning and quality of anesthesia during upper limb orthopedic surgeries. Patients and Methods: This double-blinded, randomized, clinical trial was conducted on 60 patients aged between 18 and 85 years candidated for upper limb orthopedic operations. The patients were equally and randomly distributed into two groups (n = 30). Under ultrasound imaging guidance, the first group received 7 mL of 2% lidocaine and the second group 10 mL of 1.3% lidocaine into the brachial plexus cords. The onset of block and the level of sensory and motor block were documented for each nerve territory. Results: The onset of sensory and motor block was significantly shorter in the 1.3% lidocaine group than in the 2% lidocaine group (P ≤ 0.05). The success rate of sensory and motor block was not different. The quality (completeness) of sensory block for the musculocutaneous nerve and that of motor block for the radial nerve were significantly better in the 1.3% lidocaine group than in the 2% lidocaine group. Conclusions: The volume of the injected anesthetic accelerated the onset of sensory and motor block without affecting the rate of success in our patients. PMID:26473102

  2. [Cardiotoxicity of local anesthetics].

    PubMed

    de La Coussaye, J E; Eledjam, J J; Brugada, J; Sassine, A

    1993-01-01

    The intravascular administration and the high blood resorption of local anesthetic agents are known to induce neurotoxic accidents. However, the use of potent local anesthetic drugs such as bupivacaine is responsible for serious cardiotoxic accidents with a mortality of about 50%. Indeed, bupivacaine induces both electrophysiologic and haemodynamic disturbances with the occurrence of conduction blocks, arrhythmias and cardiovascular collapse. Moreover, cardiotoxicity is worsened by: bupivacaine-induced sympathetic activation which facilitates tachycardia and arrhythmias, metabolic abnormalities such as hypoxia, acidosis, hyperkaliemia and hypothermia, pregnancy, diazepam pretreatment, and the antiarrhythmic drugs. In case of cardiac arrest, CPR must be made. In the other cases, the first treatment is to oxygenate, to intubate the trachea and to ventilate the lungs, and then to stop convulsions. Specific cardiac resuscitation remains controversial because it is based principally on experimental results. We demonstrated that the combination of clonidine and dobutamine is efficient to reverse both haemodynamic and electrophysiologic impairments induced by a large dose of bupivacaine in anesthetized dogs. Whatever the efficiency of specific resuscitation, it must be emphasized that prevention of toxic accident must always include: the best choice of local anesthetic drug (e.g.: lidocaine+alpha-2 agonist vs bupivacaine), test dose, aspiration and slow administration. Finally, the monitoring of regional anaesthesia must be similar to that in use for general anaesthesia and drugs and devices for resuscitation must be ready. PMID:8287299

  3. 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

  4. Local Anesthetic-Induced Neurotoxicity.

    PubMed

    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

  5. [Transdermal Local Anesthetics].

    PubMed

    Hanaoka, Kazuo; Arita, Hideko; Nagase, Masaki; Suzuki, Takashi; Ogawa, Sestsuro

    2015-11-01

    Taking EMLA cream and Penles tape 18 mg as examples, this article describes the conditions for skin penetration of topical anesthetics, with their onset time of action, duration of effect and a precautions for their use. EMLA cream is a unique cream for topical anesthesia which is the eutectic mixture of lidocaine and propitocaine to increase skin penetration. The safety study demonstrated that blood concentrations of active ingredients of EMLA cream were below toxic levels. EMLA cream, with confirmed high skin penetrability and safety, should be used for pain reduction of various treatments for many diseases. Here in Japan, EMLA cream has indications not only for pain reduction of skin laser therapy but also for reduction of needle puncture pain. This means the use of topical anesthesia would be expanded to wider ranges of treatments. PMID:26689066

  6. Hair transplant and local anesthetics.

    PubMed

    Lam, Samuel M

    2013-10-01

    Hair restoration is an art and a science that requires an experienced and dedicated surgeon and team to achieve consistently superior outcomes. In addition to discussion of local anesthetic in use for hair restoration, this article emphasizes the pearls and pitfalls that are involved at every phase of the procedure including judgment, hairline design, donor harvesting, recipient-site creation, graft preparation, and graft placement. Two recent advances in the field are highlighted: the use of regenerative medicine (platelet-rich plasma and ACell), and developments in follicular-unit extraction as an alternative to traditional linear donor harvesting. PMID:24093656

  7. 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

  8. Effect of Local and General Anesthetics on Interfacial Water

    PubMed Central

    2016-01-01

    Background Water undergoes structural change as it interfaces with hydrophilic surfaces, including the many hydrophilic surfaces within the cell. This interfacial water has become known as “Exclusion Zone (EZ) water” or “fourth-phase water” [1]. Methods We tested the hypothesis that anesthetics diminish the amount of EZ water, and that this change may correlate with functional changes in anesthesia. By using the local anesthetics Lidocaine and Bupivacaine as well as a general inhalational anesthetic, Isoflurane, we tracked the EZ size as these anesthetics were introduced. Results All three anesthetics diminished EZ size in a concentration-dependent manner at concentrations of 0.18 mM and greater for Bupivacaine, 0.85 mM and greater for Lidocaine, and 0.2% for Isoflurane. At extremely low (micromolar) concentrations, however, all three anesthetics increased EZ size. Conclusions The sharp increase of EZ size associated with micromolar anesthetic concentrations follows a similar pattern to induction of general anesthesia, from the excitation stage (Stage II) to the depression and overdose stages of surgical anesthesia (Stages III and IV). The results are consistent with the hypothesis that anesthetics may act on water, a fundamental organizational component common to all cells. PMID:27054588

  9. Long-acting local anesthetics in dentistry.

    PubMed Central

    Sisk, A. L.

    1992-01-01

    Long-acting local anesthetics have proved to be effective for the suppression of both intraoperative and postoperative pain. They are useful for lengthy dental treatments and for prevention of severe pain following many types of surgical procedures. Although the currently available long-acting local anesthetics for dentistry have minimal side effects in the doses usually employed, there are potential problems. Bupivacaine, for example, can cause significant cardiac depressant and dysrhythmogenic responses. Etidocaine has less pronounced effects on the cardiovascular system, but its use may be associated with inadequate control of intraoperative bleeding. A new long-acting local anesthetic, ropivacaine, appears to offer advantages over either of the currently used long-acting agents. PMID:1308373

  10. Crystallization of Local Anesthetics When Mixed With Corticosteroid Solutions

    PubMed Central

    Hwang, Hyeoncheol; Park, Jihong; Lee, Won Kyung; Lee, Woo Hyung; Leigh, Ja-Ho; Lee, Jin Joo; Chung, Sun G.; Lim, Chaiyoung; Park, Sang Jun

    2016-01-01

    Objective To evaluate at which pH level various local anesthetics precipitate, and to confirm which combination of corticosteroid and local anesthetic crystallizes. Methods Each of ropivacaine-HCl, bupivacaine-HCl, and lidocaine-HCl was mixed with 4 different concentrations of NaOH solutions. Also, each of the three local anesthetics was mixed with the same volume of 3 corticosteroid solutions (triamcinolone acetonide, dexamethasone sodium phosphate, and betamethasone sodium phosphate). Precipitation of the local anesthetics (or not) was observed, by the naked eye and by microscope. The pH of each solution and the size of the precipitated crystal were measured. Results Alkalinized with NaOH to a certain value of pH, local anesthetics precipitated (ropivacaine pH 6.9, bupivacaine pH 7.7, and lidocaine pH 12.9). Precipitation was observed as a cloudy appearance by the naked eye and as the aggregation of small particles (<10 µm) by microscope. The amount of particles and aggregation increased with increased pH. Mixed with betamethasone sodium phosphate, ropivacaine was precipitated in the form of numerous large crystals (>300 µm, pH 7.5). Ropivacaine with dexamethasone sodium phosphate also precipitated, but it was only observable by microscope (a few crystals of 10–100 µm, pH 7.0). Bupivacaine with betamethasone sodium phosphate formed precipitates of non-aggregated smaller particles (<10 µm, pH 7.7). Lidocaine mixed with corticosteroids did not precipitate. Conclusion Ropivacaine and bupivacaine can precipitate by alkalinization at a physiological pH, and therefore also produce crystals at a physiological pH when they are mixed with betamethasone sodium phosphate. Thus, the potential risk should be noted for their use in interventions, such as epidural steroid injections. PMID:26949665

  11. Hemodynamic changes following injection of local anesthetics with different concentrations of epinephrine during simple tooth extraction: A prospective randomized clinical trial

    PubMed Central

    Al-Showaikhat, Fatimah; Al-Shubbar, Fatimah; Al-Zawad, Kawther; Al-Zawad, Fatimah

    2015-01-01

    Background Presence of epinephrine in local anesthetic cartridge increases the duration of local anesthesia (LA), decreases the risk of toxicity, and provides hemostasis. However, the unfavorable effects are increasing heart rate (HR) and raising blood pressure (BP). The aim was to evaluate hemodynamic changes in the BP, HR, and oxygen saturation (SpO2) of normal patients undergoing tooth extraction using LA with various epinephrine concentrations. Material and Methods A prospective randomized clinical trial was conducted on 120 patients who were divided randomly into 3 parallel groups according to the LA received. Group 1: lidocaine 2% with epinephrine 1:80,000 (L80). Group 2: articaine 4% with epinephrine 1:100,000 (A100). Group 3: articaine 4% with epinephrine 1:200,000 (A200). Inclusion criteria: normal patients whose BP < 140/90. Exclusion criteria: hypertension, cardiovascular disease, hyperthyroidism, pregnancy, and allergy to LA. BP, HR, and (SpO2) were evaluated in 3 different time points: 3 minutes before LA, 3 minutes after LA, and 3 minutes after extraction. Results Systolic blood pressure (SBP) significantly increased after injection of L80 and continued after extraction to be significant than pre-injection. SBP significantly increased after injection of A100 then decreased after extraction. In the group of A200, SBP insignificantly decreased after injection then increased after extraction. The increasing of SBP between time point 1and 2 was significantly higher in G1 than G3 (p=0.014). Diastolic blood pressure decreased after LA in the 3 groups; however it was significant only with L80, then increased after extraction for all. Conclusions The changings of DBP, HR and SpO2 after anesthesia and extraction showed no significant difference among the three groups. However, A200 had significant lesser effect on SBP than L80 and the least effect on other parameters. Therefore, A200 is considered safer than L80 and A100 and is recommended for LA before teeth

  12. Interaction of local anesthetics with the K+ channel pore domain

    PubMed Central

    Gray, Noel W.; Zhorov, Boris S.; Moczydlowski, Edward G.

    2013-01-01

    Local anesthetics and related drugs block ionic currents of Na+, K+ and Ca2+ conducted across the cell membrane by voltage-dependent ion channels. Many of these drugs bind in the permeation pathway, occlude the pore and stop ion movement. However channel-blocking drugs have also been associated with decreased membrane stability of certain tetrameric K+ channels, similar to the destabilization of channel function observed at low extracellular K+ concentration. Such drug-dependent stability may result from electrostatic repulsion of K+ from the selectivity filter by a cationic drug molecule bound in the central cavity of the channel. In this study we used the pore domain of the KcsA K+ channel protein to test this hypothesis experimentally with a biochemical assay of tetramer stability and theoretically by computational simulation of local anesthetic docking to the central cavity. We find that two common local anesthetics, lidocaine and tetracaine, promote thermal dissociation of the KcsA tetramer in a K+-dependent fashion. Docking simulations of these drugs with open, open-inactivated and closed crystal structures of KcsA yield many energetically favorable drug-channel complexes characterized by nonbonded attraction to pore-lining residues and electrostatic repulsion of K+. The results suggest that binding of cationic drugs to the inner cavity can reduce tetramer stability of K+ channels. PMID:23545989

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

    SciTech Connect

    Mashimo, T.; Abe, K.; Yoshiya, I.

    1986-04-01

    The effects of local anesthetics and a divalent cation, Ca2+, on the function of rhodopsin were estimated from the measurements of light-induced proton uptake. The light-induced proton uptake by rhodopsin in the rod outer segment disk membrane was enhanced at lower pH (4) but depressed at higher pHs (6 to 8) by the tertiary amine local anesthetics lidocaine, bupivacaine, tetracaine, and dibucaine. The order of local anesthetic-induced depression of the proton uptake followed that of their clinical anesthetic potencies. The depression of the proton uptake versus the concentration of the uncharged form of local anesthetic nearly describes the same curve for small and large dose of added anesthetic. Furthermore, a neutral local anesthetic, benzocaine, depressed the proton uptake at all pHs between 4 and 7. These results indicate that the depression of the proton uptake is due to the effect of only the uncharged form. It is hypothesized that the uncharged form of local anesthetics interacts hydrophobically with the rhodopsin in the disk membrane. The dual effect of local anesthetics on the proton uptake, on the other hand, suggests that the activation of the function of rhodopsin may be caused by the charged form. There was no significant change in the light-induced proton uptake by rhodopsin when 1 mM of Ca2+ was introduced into the disk membrane at varying pHs in the absence or presence of local anesthetics. This fact indicates that Ca2+ ion does not influence the diprotonating process of metarhodopsin; neither does it interfere with the local anesthetic-induced changes in the rhodopsin molecule.

  14. 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...

  15. 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 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...

  16. 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 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...

  17. 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 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...

  18. 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...

  19. Pain management via local anesthetics and responsive hydrogels

    PubMed Central

    Bagshaw, Kyle R; Hanenbaum, Curt L; Carbone, Erica J; Lo, Kevin WH; Laurencin, Cato T; Walker, Joseph; Nair, Lakshmi S

    2015-01-01

    Acute and chronic pain control is a significant clinical challenge that has been largely unmet. Local anesthetics are widely used for the control of post-operative pain and in the therapy of acute and chronic pain. While a variety of approaches are currently used to prolong the duration of action of local anesthetics, an optimal strategy to achieve neural blockage for several hours to days with minimal toxicity has yet to be identified. Several drug delivery systems such as liposomes, microparticles and nanoparticles have been investigated as local anesthetic delivery vehicles to achieve prolonged anesthesia. Recently, injectable responsive hydrogels raise significant interest for the localized delivery of anesthetic molecules. This paper discusses the potential of injectable hydrogels to prolong the action of local anesthetics. PMID:25690085

  20. Articaine - the best choice of local anesthetic in contemporary dentistry.

    PubMed

    Nizharadze, N; Mamaladze, M; Chipashvili, N; Vadachkoria, D

    2011-01-01

    Local anesthesia forms the foundation of pain control techniques in clinical dentistry. Within the rich local anesthetic drugs available in dentistry for the prevention and management of pain 4% articaine solutions achieve highest level of anesthetic potency and lowest systemic toxicity in all clinical situations, prior to its superlative physicochemical characteristics and the pharmacological profile. These are - low lipid solubility, high plasma protein binding rate, fast metabolization, fast elimination half time; low blood level. Articaine inactivates in both ways: in the liver and the blood serum. It has good spreading through tissues. Thus, articaine seems to be the local anesthetic of first choice in tissues with suppurative inflammation, for adults, children (over 4), elderly, pregnant women, breastfeeding women, patients suffering from hepatic disorders and renal function impairment. In Articaine solutions (1: 200,000) epinephrine is in low concentration, thus in patients at high risk adverse responses are maximally decreased. In these patients articaine should be used with careful consideration of risk/benefit ratio. Articaine solutions must not be used in persons who are allergic or hypersensitive to sulphite, due to content of Sodium metabisulfite as vasoconstrictor's antioxidant in it. Incidence of serious adverse effects related to dental anesthesia with articaine is very low. Toxic reactions are usually due to an inadvertent intravascular injection or use of excessive dose. To avoid overdoses maximum recommendation dose (MRD) must not be exceeded and aspiration test always performed prior all LA injections. In these article we introduce new graphs providing a quick and effect way to determine maximum LA dose. If the overdose reactions develop, adherence to the basic step of emergency management with end to a successful outcome in virtually all cases. PMID:21346262

  1. Oxindole-3-spiropyrrolidines and -piperidines. Synthesis and local anesthetic activity.

    PubMed

    Kornet, M J; Thio, A P

    1976-07-01

    The synthesis and local anesthetic properties of five 1-dealkyloxindole-3-spiropyrrolidines and six 1-dealkyloxindole-3-spiropiperidines are described. The compounds studied include members of all five possible positional isomers of the two classes of spirooxindoles; all showed local anesthetic activity by the rat sciatic nerve block method. The coincidence of the least variability in the relative positions of basic nitrogen, amide carbonyl, and aromatic ring (compounds 1 and 6) with lowest normalized toxicity is noteworthy. PMID:940109

  2. Inhibition of murine cardiomyocyte respiration by amine local anesthetics.

    PubMed

    Aburawi, Elhadi H; Souid, Abdul-Kader

    2014-12-01

    The hydrophobic amino acyl amide-linked local anesthetics (e.g., lidocaine and bupivacaine) impose potent cardiac toxicity and direct mitochondrial dysfunction. To investigate these adverse events, an in vitro system was employed to measure their effects on O2 consumption (cellular respiration) by murine myocardium. Specimens were collected from the ventricular myocardium and immediately immersed in ice-cold Krebs-Henseleit buffer saturated with 95 % O2:5 % CO2. O2 concentration was determined as a function of time from the phosphorescence decay rates of Pd(II)-meso-tetra-(4-sulfonatophenyl)-tetrabenzoporphyrin. Myocardial O2 consumption was linear with time (zero-order kinetics); its rate (k, in μM O2 min(-1)), thus, was the negative of the slope of [O2] vs. time. Cyanide inhibited O2 consumption, confirming the oxidation occurred in the respiratory chain. Lidocaine and bupivacaine produced immediate and sustained inhibition of cellular respiration at plasma concentrations of the drugs (low micromolar range). Bupivacaine was twice as potent as lidocaine. The inhibition was dose-dependent, saturating at concentrations ≥30 μM. At saturating doses, lidocaine produced ~20 % inhibition and bupivacaine ~40 % inhibition. Cellular ATP was also decreased in the presence of 30 μM lidocaine or bupivacaine. The studied amines inhibited myocardial cellular respiration. This effect is consistent with their known adverse events on mitochondrial function. The described approach allows accurate assessments and comparisons of the toxic effects of local anesthetics on heart tissue bioenergetics. PMID:24254523

  3. An allergy to local anesthetics? The consequences of a misdiagnosis.

    PubMed

    Doyle, K A; Goepferd, S J

    1989-01-01

    In this case, inappropriately labeling the child as "allergic to local anesthetics", resulted in her inability to receive appropriate dental care. It was a major disservice to her and led to the potentially serious consequences of neglecting the dental disease present. The small caries lesions that would have required amalgam restorations at five years of age progressed to painful toothaches requiring stainless steel crowns and pulpal treatment. Although adverse reactions to local anesthetics are uncommon, most dentists can anticipate encountering a patient who will have an adverse reaction to a local anesthetic. This case ilustrates the need for dentists to be knowledgeable regarding the signs and symptoms of the potential adverse reactions and their appropriate management. Most importantly, prevention is based upon knowledge of anatomy, dose determination, and the use of proper armamentarium and technique, which are key factors in making a safe and effective drug even safer. PMID:2723199

  4. Antifungal activity of local anesthetics against Candida species.

    PubMed Central

    Pina-Vaz, C; Rodrigues, A G; Sansonetty, F; Martinez-De-Oliveira, J; Fonseca, A F; Mårdh, P A

    2000-01-01

    OBJECTIVE: To evaluate the activity of benzydamine, lidocaine, and bupivacaine, three drugs with local anesthetic activity, against Candida albicans and non-albicans strains and to clarify their mechanism of activity. METHODS: The minimal inhibitory concentration (MIC) was determined for 20 Candida strains (18 clinical isolates and two American Type Culture Collection strains). The fungistatic activity was studied with the fluorescent probe FUN-1 and observation under epifluorescence microscopy and flow cytometry. The fungicidal activity of the three drugs was assayed by viability counts. Membrane alterations induced in the yeast cells were evaluated by staining with propidium iodide, by quantitation of intracellular K+ leakage and by transmission electron microscopy of intact yeast cells and prepared spheroplasts. RESULTS: The MIC ranged from 12.5-50.0 microg/mL, 5.0-40.0 mg/mL, and 2.5-10.0 mg/mL for benzydamine, lidocaine, and bupivacaine, respectively. The inhibitory activity of these concentrations could be detected with the fluorescent probe FUN-1 after incubation for 60 minutes. A very fast fungicidal activity was shown by 0.2, 50, and 30 mg/mL of benzydamine, lidocaine, and bupivacaine, respectively. CONCLUSIONS: At lower concentrations, the tested drugs have a fungistatic activity, due to yeast metabolic impairment, while at higher concentrations they are fungicidal, due to direct damage to the cytoplasmic membrane. PMID:10968594

  5. 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

  6. 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.

  7. Lipid Emulsions Enhance the Norepinephrine-Mediated Reversal of Local Anesthetic-Induced Vasodilation at Toxic Doses

    PubMed Central

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

    2013-01-01

    Purpose 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. Materials and Methods 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. Results 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. Conclusion 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. PMID:24142661

  8. Effect of adjuvants on the action of local anesthetics in isolated rat sciatic nerves

    PubMed Central

    Yilmaz, Eser; Gold, Michael S.; Hough, Karen A.; Gebhart, G.F.; Williams, Brian A.

    2013-01-01

    Background and Objectives There is increasing clinical use of adjuvant drugs to prolong the duration of local anesthetic-induced block of peripheral nerves. However, the mechanistic understanding regarding drug interactions between these compounds in the periphery is quite limited. Accordingly, we undertook this study to determine whether selected adjuvants are efficacious in blocking action potential propagation in peripheral nerves at concentrations used clinically, and whether these drugs influence peripheral nerve block produced by local anesthetics. Methods Isolated rat sciatic nerves were used to assess (1) the efficacy of buprenorphine, clonidine, dexamethasone, or midazolam, alone and in combination, on action potential propagation; and (2) their influence on the blocking actions of local anesthetics ropivacaine and lidocaine. Compound action potentials (CAPs) from A- and C-fibers were studied before and after drug application. Results At estimated clinical concentrations, neither buprenorphine nor dexamethasone affected either A- or C-waves of the CAP. Clonidine produced a small, but significant attenuation of the C-wave amplitude. Midazolam attenuated both A- and C-wave amplitudes, but with greater potency on the C-wave. The combination of clonidine, buprenorphine, and dexamethasone had no influence on the potency or duration of local anesthetic- or midazolam-induced block of A-and C-waves of the CAP. Conclusions These results suggest that the reported clinical efficacy of clonidine, buprenorphine, and dexamethasone influence the actions of local anesthetics via indirect mechanisms. Further identification of these indirect mechanisms may enable the development of novel approaches to achieve longer duration, modality-specific peripheral nerve block. PMID:22430023

  9. State-Dependent Inhibition of Sodium Channels by Local Anesthetics: A 40-Year Evolution.

    PubMed

    Wang, G-K; Strichartz, G R

    2012-04-01

    Knowledge about the mechanism of impulse blockade by local anesthetics has evolved over the past four decades, from the realization that Na(+) channels were inhibited to affect the impulse blockade to an identification of the amino acid residues within the Na(+) channel that bind the local anesthetic molecule. Within this period appreciation has grown of the state-dependent nature of channel inhibition, with rapid binding and unbinding at relatively high affinity to the open state, and weaker binding to the closed resting state. Slow binding of high affinity for the inactivated state accounts for the salutary therapeutic as well as the toxic actions of diverse class I anti-arrhythmic agents, but may have little importance for impulse blockade, which requires concentrations high enough to block the resting state. At the molecular level, residues on the S6 transmembrane segments in three of the homologous domains of the channel appear to contribute to the binding of local anesthetics, with some contribution also from parts of the selectivity filter. Binding to the inactivated state, and perhaps the open state, involves some residues that are not identical to those that bind these drugs in the resting state, suggesting spatial flexibility in the "binding site". Questions remaining include the mechanism that links local anesthetic binding with the inhibition of gating charge movements, and the molecular nature of the theoretical "hydrophobic pathway" that may be critical for determining the recovery rates from blockade of closed channels, and thus account for both therapeutic and cardiotoxic actions. PMID:23710324

  10. Investigation of the transdermal transport of charged local anesthetics in the presence of triterpene saponin glycosides.

    PubMed

    Pino, Christopher J; Scherer, Michael A; Shastri, V Prasad

    2014-04-01

    Percutaneous absorption and transdermal delivery of water-soluble drugs have proven to be challenging due to their low permeability through skin. Avicins which are triterpene saponin glycosides (TSGs) derived from the desert plant Acacia victoriae have not been investigated to date as chemical penetration enhancers due to their higher molecular weight (MW 2,000 Da). It was recently shown that avicins exhibit remarkable mobility across skin lipids in spite of their large size due to their unique chemical structure. In this study, the permeation of local anesthetics, lidocaine-HCl, prilocaine-HCl, and bupivacaine-HCL from aqueous vehicle, across full-thickness porcine skin was investigated in the presence of F094-a mixture of avicins. F094 was capable of enhancing the permeability of all three anesthetics from aqueous formulations at extremely low concentrations ranging from 0.1 to 1 % w/v. The enhancement, which ranged from 2- to 5-fold, was surprisingly independent of molecular weight of the anesthetics and showed clear correlation with aqueous phase solubility of the anesthetics. Since F094 was found to have no impact on the octanol/water partition coefficients of the anesthetics, this suggests that TSGs like avicins most likely impact the aqueous pathways (pericellular/pores within lipids) and as such represent an alternative means of enhancing the transdermal transport of charged drugs from water-based formulations. PMID:25786727

  11. 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. PMID:16719602

  12. Effects of local anesthetics on contractions of pregnant and non-pregnant rat myometrium in vitro.

    PubMed

    Wei, Jin-Song; Jin, Zhe-Bin; Yin, Zhi-Qiang; Xie, Qiang-Min; Chen, Ji-Qiang; Li, Zi-Gang; Tang, Hui-Fang

    2014-06-01

    In order to determine whether local anesthetics directly affect the propagation and strength of myometrial contractions, we compared the effects of bupivacaine, ropivacaine, lidocaine and tetracaine on the contractions of myometrium isolated from pregnant and non-pregnant rats. Full-thickness myometrial strips were obtained from 18- to 21-day pregnant and non-pregnant Sprague-Dawley rats and incubated in an organ bath. When spontaneous contractions became regular, strips were exposed to cumulative concentrations of the four local anesthetics ranging from 0.01 to 300 μmol/L and the amplitude and frequency of contraction were recorded. All four compounds caused a concentration-dependent inhibition of the contractility of pregnant and non-pregnant uterine muscle. In pregnant myometrium, the concentration that caused 50% inhibition (IC(50)) was 100 μmol/L for bupivacaine, 157 μmol/L for ropivacaine, > 1000 μmol/L for lidocaine, and 26.3 μmol/L for tetracaine. In non-pregnant myometrium, the IC(50) was 26.9 μmol/L for bupivacaine, 40 μmol/L for ropivacaine, 384 μmol/L for lidocaine, and 7.4 μmol/L for tetracaine. These results suggested that local anesthetics do inhibit myometrial contractions in pregnant and non-pregnant rats in a concentration-dependent manner. PMID:24901082

  13. [A simple anesthetic system with oxygen concentrator for war or disaster situation].

    PubMed

    Suzuki, Takao; Asai, Sunao

    2003-06-01

    An oxygen concentrator is commonly used as an oxygen source in war or disaster situation. We examined the possibility of using the oxygen concentrator, capable of producing 7 l.min-1 of oxygen, for anesthetic circuit. When the oxygen concentrator is connected with an ordinary anesthetic vaporizer, the gas flow from the vaporizer is 6 l.min-1 and its vaporization is the same as when it is used with a high gas pressure. With this oxygen concentrator, it is possible to make a simple anesthetic system with an ordinary vaporizer, not a special vaporizer for draw over anesthetic system. PMID:12854486

  14. From cocaine to ropivacaine: the history of local anesthetic drugs.

    PubMed

    Ruetsch, Y A; Böni, T; Borgeat, A

    2001-08-01

    In 1850, about three centuries after the conquest of Peru by Pizzaro, the Austrian von Scherzer brought a sufficient quantum of coca leaves to Europe to permit the isolation of cocaine. As suggested by his friend Sigmund Freud, descriptions of the properties of the coca prompted the Austrian Koller to perform in 1884 the first clinical operation under local anesthesia, by administration of cocaine on the eye. The use of cocaine for local and regional anesthesia rapidly spread throughout Europe and America. The toxic effects of cocaine were soon identified resulting in many deaths among both patients and addicted medical staff. Local anesthesia was in a profound crisis until the development of modern organic chemistry which led to the synthesis of pure cocaine in 1891. New amino ester local anesthetics were synthesized between 1891 and 1930, such as tropocaine, eucaine, holocaine, orthoform, benzocaine, and tetracaine. In addition, amino amide local anesthetics were prepared between 1898 and 1972 including nirvaquine, procaine, chloroprocaine, cinchocaine, lidocaine, mepivacaine, prilocaine, efocaine, bupivacaine, etidocaine, and articaine. All of these drugs were ostensibly less toxic than cocaine, but they had differing amounts of central nervous system (CNS) and cardiovascular (CV) toxicity. Bupivacaine is of special interest because of its long duration of action and history of clinical application. Synthesized in 1957, the introduction of bupivacaine on the market in 1965 paralleled the progressive and cumulative reports of CNS and CV toxicity, leading to the restriction of its use and the identification of a special therapy-resistant CV toxicity. Numerous experimental studies were conducted to identify the fine cellular mechanism of this toxicity, which refines our understanding of the action of local anesthetics. The identification of optically active isomers of the mepivacaine family led to the selection of ropivacaine, a pure S-(-) enantiomer, whose

  15. Loss of Anatomical Landmarks with Eutectic Mixture of Local Anesthetic Cream for Neonatal Male Circumcision

    PubMed Central

    Plank, Rebeca M.; Kubiak, David W.; Abdullahi, Rasak Bamidele; Ndubuka, Nnamdi; Nkgau, Maggie M.; Dapaah-Siakwan, Fredrick; Powis, Kathleen M.; Lockman, Shahin

    2012-01-01

    We report two cases of newborns who developed marked local edema after application of a eutectic mixture of local anesthetic (EMLA) topical anesthetic cream for neonatal male circumcision (NMC). Although local edema and erythema are known potential side effects of EMLA cream, a common anesthetic used for NMC, the loss of landmarks precluding safe NMC has not previously been reported, and is described here. Although we cannot recommend an alternate local anesthetic for neonates with this reaction to EMLA, based on a review of the published data we think that serious systemic adverse events related to EMLA are extremely rare. PMID:23102766

  16. Development of Bioadhesive Transdermal Bupivacaine Gels for Enhanced Local Anesthetic Action

    PubMed Central

    Cho, Cheong-Weon; Kim, Deok-Bae; Shin, Sang-Chul

    2012-01-01

    Topical drug dosage forms such as ointments and creams can be easily removed through wetting, movement and contact. The new bioadhesive formulations with enhanced local anesthetic effects are needed for topical administration. The adhesive capacity of hydroxypropyl methylcellulose (HPMC) was determined by measuring the maximum detachment force and the adhesion work with an auto peeling tester. The release of drug from a HPMC gel was studied according to the drug concentration. Permeation study through the rat skin was performed at 37°C using phosphate buffer solution (pH = 7.4) as a receptor medium. To increase the skin permeation of bupivacaine from the HPMC gels, penetration enhancer such as the saturated and unsaturated fatty acids, the pyrrolidones, the propylene glycol derivatives, the glycerides, and the non-ionic surfactants were incorporated in the bupivacaine-HPMC gels. The local anesthetic effect of the formulated gel preparation was examined using a tail-flick analgesimeter. As the concentration of HPMC increased, the bioadhesive force and viscosity were increased. The rate of drug release was increased with increasing the drug concentration. Among the enhancers used, polyoxyethylene 2-oleyl ether showed the most enhancing effects on drug permeation through the skin. In the rat tail flick test, the area under the efficacy curve of bupivacaine gel containing polyoxyethylene 2-oleyl ether and tetrahydrozoline showed a 2.36-fold increase in anesthetic activity compared to control gel without any additives. The bupivacaine gels containing both penetration enhancer and vasoconstrictor showed enhancement and prolonged efficacy compared to the control gel. To enhance the local anesthetic effects of bupivacaine, the transdermal bupivacaine gel formulation containing penetration enhancer and vasoconstrictor could be developed. PMID:24250466

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

    PubMed Central

    Zorzetto, Laura; Brambilla, Paola; Marcello, Elena; Bloise, Nora; De Gregori, Manuela; Cobianchi, Lorenzo; Peloso, Andrea; Allegri, Massimo; Visai, Livia; Petrini, Paola

    2016-01-01

    Local anesthetics block the transmission of painful stimuli to the brain by acting on ion channels of nociceptor fibers, and find application in the management of acute and chronic pain. Despite the key role they play in modern medicine, their cardio and neurotoxicity (together with their short half-life) stress the need for developing implantable devices for tailored local drug release, with the aim of counterbalancing their side effects and prolonging their pharmacological activity. This review discusses the evolution of the physical forms of local anesthetic delivery systems during the past decades. Depending on the use of different biocompatible materials (degradable polyesters, thermosensitive hydrogels, and liposomes and hydrogels from natural polymers) and manufacturing processes, these systems can be classified as films or micro- or nanostructured devices. We analyze and summarize the production techniques according to this classification, focusing on their relative advantages and disadvantages. The most relevant trend reported in this work highlights the effort of moving from microstructured to nanostructured systems, with the aim of reaching a scale comparable to the biological environment. Improved intracellular penetration compared to microstructured systems, indeed, provides specific drug absorption into the targeted tissue and can lead to an enhancement of its bioavailability and retention time. Nanostructured systems are realized by the modification of existing manufacturing processes (interfacial deposition and nanoprecipitation for degradable polyester particles and high- or low-temperature homogenization for liposomes) or development of novel strategies (electrospun matrices and nanogels). The high surface-to-volume ratio that characterizes nanostructured devices often leads to a burst drug release. This drawback needs to be addressed to fully exploit the advantage of the interaction between the target tissues and the drug: possible strategies

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

    PubMed

    Zorzetto, Laura; Brambilla, Paola; Marcello, Elena; Bloise, Nora; De Gregori, Manuela; Cobianchi, Lorenzo; Peloso, Andrea; Allegri, Massimo; Visai, Livia; Petrini, Paola

    2016-01-01

    Local anesthetics block the transmission of painful stimuli to the brain by acting on ion channels of nociceptor fibers, and find application in the management of acute and chronic pain. Despite the key role they play in modern medicine, their cardio and neurotoxicity (together with their short half-life) stress the need for developing implantable devices for tailored local drug release, with the aim of counterbalancing their side effects and prolonging their pharmacological activity. This review discusses the evolution of the physical forms of local anesthetic delivery systems during the past decades. Depending on the use of different biocompatible materials (degradable polyesters, thermosensitive hydrogels, and liposomes and hydrogels from natural polymers) and manufacturing processes, these systems can be classified as films or micro- or nanostructured devices. We analyze and summarize the production techniques according to this classification, focusing on their relative advantages and disadvantages. The most relevant trend reported in this work highlights the effort of moving from microstructured to nanostructured systems, with the aim of reaching a scale comparable to the biological environment. Improved intracellular penetration compared to microstructured systems, indeed, provides specific drug absorption into the targeted tissue and can lead to an enhancement of its bioavailability and retention time. Nanostructured systems are realized by the modification of existing manufacturing processes (interfacial deposition and nanoprecipitation for degradable polyester particles and high- or low-temperature homogenization for liposomes) or development of novel strategies (electrospun matrices and nanogels). The high surface-to-volume ratio that characterizes nanostructured devices often leads to a burst drug release. This drawback needs to be addressed to fully exploit the advantage of the interaction between the target tissues and the drug: possible strategies

  19. Extended duration local anesthetic agent in a rat paw model.

    PubMed

    Ickowicz, D E; Golovanevski, L; Domb, A J; Weiniger, C F

    2014-07-01

    Encapsulated local anesthetics extend postoperative analgesic effect following site-directed nerve injection; potentially reducing postoperative complications. Our study aim was to investigate efficacy of our improved extended duration formulation - 15% bupivacaine in poly(DL-lactic acid co castor oil) 3:7 synthesized by ring opening polymerization. In vitro, around 70% of bupivacaine was released from the p(DLLA-CO) 3:7 after 10 days. A single injection of the optimal formulation of 15% bupivacaine-polymer or plain (0.5%) bupivacaine (control), was injected via a 22G needle beside the sciatic nerve of Sprague-Dawley rats under anesthesia; followed (in some animals) by a 1cm longitudinal incision through the skin and fascia of the paw area. Behavioral tests for sensory and motor block assessment were done using Hargreave's hot plate score, von Frey filaments and rearing count. The 15% bupivacaine formulation significantly prolonged sensory block duration up to at least 48 h. Following surgery, motor block was observed for 48 h following administration of bupivacaine-polymer formulation and rearing was reduced (returning to baseline after 48 h). No significant differences in mechanical nociceptive response were observed. The optimized bupivacaine-polymer formulation prolonged duration of local anesthesia effect in our animal model up to at least 48 h. PMID:24726301

  20. Direct inhibition of the actomyosin motility by local anesthetics in vitro.

    PubMed Central

    Tsuda, Y; Mashimo, T; Yoshiya, I; Kaseda, K; Harada, Y; Yanagida, T

    1996-01-01

    Using a recently developed in vitro motility assay, we have demonstrated that local anesthetics directly inhibit myosin-based movement of single actin filaments in a reversible dose-dependent manner. This is the first reported account of the actions of local anesthetics on purified proteins at the molecular level. In this study, two tertiary amine local anesthetics, lidocaine and tetracaine, were used. The inhibitory action of the local anesthetics on actomyosin sliding movement was pH dependent; the anesthetics were more potent at higher pH values, and this reaction was accompanied by an increased proportion of the uncharged form of the anesthetics. QX-314, a permanently charged derivative of lidocaine, had no effect on actomyosin sliding movement. These results indicate that the uncharged form of local anesthetics is predominantly responsible for the inhibition of actomyosin sliding movement. The local anesthetics inhibited sliding movement but hardly interfered with the binding of actin filaments to myosin on the surface or with actomyosin ATPase activity at low ionic strength. To characterize the actomyosin interaction in the presence of anesthetics, we measured the binding and breaking force of the actomyosin complex. The binding of actin filaments to myosin on the surface was not affected by lidocaine at low ionic strength. The breaking force, measured using optical tweezers, was approximately 1.5 pN per micron of an actin filament, which was much smaller than in rigor and isometric force. The binding and breaking force greatly decreased with increasing ionic strength, indicating that the remaining interaction is ionic in nature. The result suggests that the binding and ATPase of actomyosin are governed predominantly by ionic interaction, which is hardly affected by anesthetics; whereas the force generation requires hydrophobic interaction, which plays a major part of the strong binding and is blocked by anesthetics, in addition to the ionic interaction

  1. Polymeric alginate nanoparticles containing the local anesthetic bupivacaine.

    PubMed

    Grillo, Renato; de Melo, Nathalie F S; de Araújo, Daniele Ribeiro; de Paula, Eneida; Rosa, André Henrique; Fraceto, Leonardo Fernandes

    2010-11-01

    Bupivacaine (BVC; S75–R25, NovaBupi® is an amide-type local anesthetic. Sodium alginate is a water-soluble linear polysaccharide. The present study reports the development of alginate/bis(2-ethylhexyl) sulfosuccinate (AOT) and alginate/chitosan nanoparticle formulations containing BVC (0.5%). The amounts of BVC associated in the alginate/AOT and alginate/chitosan nanoparticles were 87 ± 1.5 and 76 ± 0.9%, respectively. The average diameters and zeta potentials of the nanoparticles were measured for 30 days, and the results demonstrated the good stability of these particles in solution. The in vitro release kinetics showed a different behavior for the release profile of BVC in solution, compared with BVC-loaded alginate nanoparticles. In vitro and in vivo assays showed that alginate–chitosan BVC (BVC(ALG–CHIT)) and alginate–AOT BVC (BVC(ALG–AOT)) presented low cytotoxicity in 3T3-fibroblasts, enhanced the intensity, and prolonged the duration of motor and sensory blockades in a sciatic nerve blockade model. PMID:20196632

  2. The effects of opioids, local anesthetics and adjuvants on isolated pregnant rat uterine muscles.

    PubMed

    Nacitarhan, C; Sadan, G; Kayacan, N; Ertugrul, F; Arici, G; Karsli, B; Erman, M

    2007-05-01

    Local anaesthetics, opioids and adjuvants are often used for managing labor pain. Some others of these agents are reported to cause alterations on uterine contractility during labor. However, there are controversies and the effects of some others are unknown. In the present study, we aimed to elucidate the effects of opioids such as alfentanyl, meperidine, remifentanyl; local anesthetics such as mepivacaine, ropivacaine, bupivacaine; and adjuvants such as clonidine and midazolam on isolated pregnant rat uterine muscle. Strips of longitudinal uterine smooth muscle obtained from rats pregnant for 18-21 days were suspended in 20 ml organ baths. Isometric tension was continuously measured with an isometric force transducer connected to a computer-based data acquisition system. The effects of cumulative concentrations of alfentanyl, meperidine, remifentanyl, mepivacaine, ropivacaine, bupivacaine, clonidine and midazolam (10(-8) - 10(-4) M, for all) on contractions induced by oxytocin (1 mU/ml) were studied. Alfentanyl (10(-5) M), meperidine (10(-5) M), remifentanyl (10(-4) M), bupivacaine (10(-4) M), ropivacaine (10(-4) M) and midazolam (3 x 10(-5) M) caused significant decreases in contractile responses of uterine strips to oxytocin. Contrastingly, mepivacaine increased (33.1% +/- 7.2%) oxytocin-induced contractions of uterine strips while clonidine exerted no significant effect. The sensitivity of myometrial preparations to tested local anesthetics or opioids did not differ significantly. The findings of the present study demonstrated that some local anesthetics, opioids and adjuvants caused significant and agent-specific alterations on contractility of the pregnant rat myometrium. Therefore, they seemed to have a potential to influence uterine contractility during clinical management of pain during labor. However, further research is needed to extrapolate these finding to clinical practice. PMID:17609740

  3. New Updates Pertaining to Drug Delivery of Local Anesthetics in Particular Bupivacaine Using Lipid Nanoparticles.

    PubMed

    Beiranvand, Siavash; Eatemadi, Ali; Karimi, Arash

    2016-12-01

    Lipid nanoparticles (liposomes) were first described in 1965, and several work have led to development of important technical advances like triggered release liposomes and drug-loaded liposomes. These advances have led to numerous clinical trials in such diverse areas such as the delivery of anti-cancer, antifungal, and antibiotic drugs; the delivery of gene medicines; and most importantly the delivery of anesthesia drugs. Quite a number of liposomes are on the market, and many more are still in developmental stage. Lipid nanoparticles are the first nano-medicine delivery system to be advanced from laboratory concept to clinical application with high considerable clinical acceptance. Drug delivery systems for local anesthetics (LAs) have caught the interest of many researchers because there are many biomedical advantages connected to their application. There have been several formulation techniques to systemically deliver LA that include encapsulation in liposomes and complexation in cyclodextrins, nanoparticles, and to a little extent gold nanoparticles. The proposed formulations help to decrease the LA concentration utilized, increase its permeability, and most importantly increase the localization of the LA for a long period of time thereby leading to increase in the duration of the LA effect and finally to reduce any local and systemic toxicity. In this review, we will highlight on new updates pertaining to drug delivery of local anesthetics in particular bupivacaine using lipid nanoparticles. PMID:27342601

  4. New Updates Pertaining to Drug Delivery of Local Anesthetics in Particular Bupivacaine Using Lipid Nanoparticles

    NASA Astrophysics Data System (ADS)

    Beiranvand, Siavash; Eatemadi, Ali; Karimi, Arash

    2016-06-01

    Lipid nanoparticles (liposomes) were first described in 1965, and several work have led to development of important technical advances like triggered release liposomes and drug-loaded liposomes. These advances have led to numerous clinical trials in such diverse areas such as the delivery of anti-cancer, antifungal, and antibiotic drugs; the delivery of gene medicines; and most importantly the delivery of anesthesia drugs. Quite a number of liposomes are on the market, and many more are still in developmental stage. Lipid nanoparticles are the first nano-medicine delivery system to be advanced from laboratory concept to clinical application with high considerable clinical acceptance. Drug delivery systems for local anesthetics (LAs) have caught the interest of many researchers because there are many biomedical advantages connected to their application. There have been several formulation techniques to systemically deliver LA that include encapsulation in liposomes and complexation in cyclodextrins, nanoparticles, and to a little extent gold nanoparticles. The proposed formulations help to decrease the LA concentration utilized, increase its permeability, and most importantly increase the localization of the LA for a long period of time thereby leading to increase in the duration of the LA effect and finally to reduce any local and systemic toxicity. In this review, we will highlight on new updates pertaining to drug delivery of local anesthetics in particular bupivacaine using lipid nanoparticles.

  5. Computer simulations of local anesthetic mechanisms: Quantum chemical investigation of procaine

    SciTech Connect

    Smith, Jeremy C; Bondar, A.N.; Suhai, Sandor; Frangopol, P.T.

    2007-02-01

    A description at the atomic level of detail of the interaction between local anesthetics, lipid membranes and membrane proteins, is essential for understanding the mechanism of local anesthesia. The importance of performing computer simulations to decipher the mechanism of local anesthesia is discussed here in the context of the current status of understanding of the local anesthetics action. As a first step towards accurate simulations of the interaction between local anesthetics, proteins, lipid and water molecules, here we use quantum mechanical methods to assess the charge distribution and structural properties of procaine in the presence and in the absence of water molecules. The calculations indicate that, in the absence of hydrogen-bonding water molecules, protonated procaine strongly prefers a compact structure enabled by intramolecular hydrogen bonding. In the presence of water molecules the torsional energy pro?le of procaine is modified, and hydrogen bonding to water molecules is favored relative to intra-molecular hydrogen bonding.

  6. Differential mechanism of the effects of ester-type local anesthetics on sarcoplasmic reticulum Ca-ATPase.

    PubMed

    Sánchez, G A; Di Croce, D E; de la Cal, C; Richard, S B; Takara, D

    2013-12-01

    The effect of the local anesthetics procaine and tetracaine on sarcoplasmic reticulum membranes isolated from two masticatory muscles, masseter and medial pterygoid, was tested and compared to fast-twitch muscles. The effects of the anesthetics on Ca-ATPase activity, calcium binding, uptake, and phosphorylation of the enzyme by inorganic phosphate (Pi) were tested with radioisotopic methods. Calcium binding to the Ca-ATPase was non-competitively inhibited, and the enzymatic activity decreased in a concentration-dependent manner. The inhibition of the activity depended on pH, calcium concentration, the presence of the calcium ionophore calcimycin, and the membrane protein concentration. Unlike fast-twitch membranes, the pre-exposure of the masseter and medial pterygoid membranes to the anesthetics enhanced the enzymatic activity in the absence of calcimycin, supporting their permeabilizing effect. Procaine and tetracaine also interfered with the calcium transport capability, decreasing the maximal uptake without modification of the calcium affinity for the ATPase. Besides, the anesthetics inhibited the phosphorylation of the enzyme by Pi in a competitive manner. Tetracaine revealed a higher inhibitory potency on Ca-ATPase compared to procaine, and the inhibitory concentrations were lower than usual clinical doses. It is concluded that procaine and tetracaine not only affect key steps of the Ca-ATPase enzymatic cycle but also exert an indirect effect on membrane permeability to calcium and suggest that the consequent myoplasmic calcium increase induced by the anesthetics might account for myotoxic effects, such as sustained contraction and eventual rigidity of both fast-twitch and masticatory muscles. PMID:23949087

  7. Efficacy of Intra-articular Local Anesthetics in Total Knee Arthroplasty.

    PubMed

    Fang, Rui; Liu, Zhenfeng; Alijiang, Asila; Jia, Heng; Deng, Yingjie; Song, Yucheng; Meng, Qingcai

    2015-07-01

    Pain management after total knee arthroplasty (TKA) remains among the most important challenges for patients with TKA. Intra-articular local anesthetic has been shown to reduce postoperative pain following TKA. However, studies report conflicting results. This meta-analysis evaluated the efficacy and safety of single-dose intra-articular local anesthetics for pain control after TKA. Databases (Cochrane Central Register of Controlled Trials, Embase, PubMed, Web of Science, and Chinese Biomedical Databases) were searched to identify randomized, controlled trials comparing local anesthetic with placebo in patients undergoing TKA. Data were extracted independently by 2 researchers using a standardized form. Risk of bias was assessed with the use of the Cochrane Collaboration's tool for assessing the risk of bias by 2 observers. Relative risk, standardized mean difference, and corresponding 95% confidence interval were calculated. Seventeen trials met the inclusion criteria, for a total of 1338 participants. The results showed that, compared with the placebo group, the single local anesthetic group had a significant lower pain score with rest at 4, 8, 24, and 48 hours; less opioid consumption at 24, 48, and 72 hours postoperatively; and greater range of motion at 24, 48, and 72 hours. There were no significant differences between the 2 groups in length of hospital stay, nausea and vomiting, pruritus, sedation, or deep venous thrombosis. The study findings showed that pain relief after TKA was significantly better with intra-articular local anesthetic than with placebo. PMID:26186318

  8. 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. PMID:26302690

  9. Operating-room venting of trace concentrations of inhalation anesthetic agents.

    PubMed Central

    Oulton, J. L.

    1977-01-01

    Operating-room personnel exposed over a long period to trace concentrations of anesthetic gases may acquire both organic disturbances and impairment of cerebral function, though this has not been proven. However, the dangers of miscalculations due to disturbances of cerebral function and the fact that all working personnel should be breathing unpolluted air are sufficient indications to make scavenging of anesthetic gases mandatory. Scavenging has been carried out in many hospitals. At Vancouver General Hospital venting of the gases has decreased the nitrous oxide pollution to what is considered an acceptable level. Images FIG. 1 FIG. 5 PMID:861867

  10. On Beyond Lidocaine: Reconsidering Local Anesthetics in Tumescent Liposuction-A Critical Review.

    PubMed

    Hsia, Henry C

    2016-02-01

    The use of tumescent solution in liposuction is now considered standard of care; however, much debate still exists regarding its ideal components, especially surrounding the inclusion of local anesthetics. This article reviews the discussion regarding the use of local anesthetics in tumescent liposuction and how it may evolve in the future. The need for local anesthetic additives in tumescent liposuction has been questioned, and the use of longer-acting agents discouraged; however, increasing number of reports in recent years have described the increasingly widespread use of tumescent anesthesia where a wetting solution is infiltrated to achieve anesthesia in an operative field for procedures other than liposuction. More high-level evidence, such as randomized controlled clinical trials, will be required; however, it should be possible to develop a useful standardized algorithm that can guide surgeons to optimize patient safety as well as patient experience. PMID:26808738

  11. Tracking local anesthetic effects using a novel perceptual reference approach.

    PubMed

    Ettlin, Dominik A; Lukic, Nenad; Abazi, Jetmir; Widmayer, Sonja; Meier, Michael L

    2016-03-01

    Drug effects of loco-regional anesthetics are commonly measured by unidimensional pain rating scales. These scales require subjects to transform their perceptual correlates of stimulus intensities onto a visual, verbal, or numerical construct that uses a unitless cognitive reference frame. The conceptual understanding and execution of this magnitude estimation task may vary among individuals and populations. To circumvent inherent shortcomings of conventional experimental pain scales, this study used a novel perceptual reference approach to track subjective sensory perceptions during onset of an analgesic nerve block. In 34 male subjects, nociceptive electric stimuli of 1-ms duration were repetitively applied to left (target) and right (reference) mandibular canines every 5 s for 600 s, with a side latency of 1 ms. Stimulus strength to the target canine was programmed to evoke a tolerable pain intensity perception and remained constant at this level throughout the experiment. A dose of 0.6 ml of articaine 4% was submucosally injected at the left mental foramen. Subjects then reported drug effects by adjusting the stimulus strength (in milliamperes) to the reference tooth, so that the perceived intensity in the reference tooth was equi-intense to the target tooth. Pain and stimulus perception offsets were indicated by subjects. Thus, the current approach for matching the sensory experience in one anatomic location after regional anesthesia allows detailed tracking of evolving perceptual changes in another location. This novel perceptual reference approach facilitates direct and accurate quantification of analgesic effects with high temporal resolution. We propose using this method for future experimental investigations of analgesic/anesthetic drug efficacy. PMID:26792885

  12. New procedure to synthesize silver nanoparticles and their interaction with local anesthetics

    PubMed Central

    Mocanu, Aurora; Pasca, Roxana Diana; Tomoaia, Gheorghe; Garbo, Corina; Frangopol, Petre T; Horovitz, Ossi; Tomoaia-Cotisel, Maria

    2013-01-01

    Silver nanoparticles (AgNPs) were prepared in aqueous colloid dispersions by the reduction of Ag+ with glucose in alkaline medium. Tetraethyl orthosilicate and L-asparagine were added as stabilizers of NPs. The AgNPs were characterized, and their interaction with three local anesthetics (procaine, dibucaine, or tetracaine) was investigated. Optical spectra show the characteristic absorption band of AgNPs, due to surface plasmon resonance. Modifications in the position and shape of this band reflect the self-assembly of metal NPs mediated by anesthetic molecules and the progress in time of the aggregation process. Zeta-potential measuring was applied in order to characterize the electrostatic stability of the NPs. The size and shape of the AgNPs, as well as the features of the assemblies formed by their association in the presence of anesthetics, were evidenced by transmission electron microscopy images. Atomic force microscopy images showed the characteristics of the films of AgNPs deposited on glass support. The effect of the anesthetics could be described in terms of electrostatic forces between the negatively charged AgNPs and the anesthetic molecules, existing also in their cationic form at the working pH. But also hydrophobic and hydrogen bonding interactions between the coated nanoparticles and anesthetics molecular species should be considered. PMID:24143090

  13. Nanogel scavengers for drugs: Local anesthetic uptake by thermoresponsive nanogels

    PubMed Central

    Hoare, Todd; Sivakumaran, Daryl; Stefanescu, Cristina; Lawlor, Michael W.; Kohane, Daniel S.

    2012-01-01

    The use of functional nanogels based on poly(N-isopropylacrylamide) for effectively scavenging compounds (here, the model drug bupivacaine) is demonstrated using an in vitro cell-based assay. Nanogels containing higher loadings of acidic functional groups or more core-localized functional group distributions bound more bupivacaine, while nanogel size had no significant effect on drug binding. Increasing the dose of nanogel applied also facilitated more bupivacaine binding for all nanogel compositions tested. Binding was driven predominantly by acid-base interactions between the nanogels (anionic) and bupivacaine (cationic) at physiological pH, although both non-specific absorption and hydrophobic partitioning also contributed to drug scavenging. Nanogels exhibited minimal cytotoxicity to multiple cell types and were well-tolerated in vivo via peritoneal injections, although larger nanogels caused limited splenic toxicity at higher concentrations. The cell-based assay described herein is found to facilitate more robust drug uptake measurements for nanogels than conventional centrifugation-based assays, in which nanogels can be compressed (and thus drug released) during the measurement. PMID:22244983

  14. Effect of local anesthetics on the organization and dynamics in membranes of varying phase: A fluorescence approach.

    PubMed

    Shrivastava, Sandeep; Dutta, Diya; Chattopadhyay, Amitabha

    2016-06-01

    The molecular mechanism underlying the action of local anesthetics remains elusive. Phenylethanol (PEtOH) is an ingredient of essential oils with a rose-like odor and has been used as a local anesthetic. In this work, we explored the effect of PEtOH on organization and dynamics in membranes representing various biologically relevant phases using differentially localized fluorescent membrane probes, DPH and TMA-DPH. We show here that PEtOH induces disorder in membranes of all phases (gel/fluid/liquid-ordered). However, the extent of membrane disorder varies in a phase-specific manner. Maximum membrane disordering was observed in gel phase, followed by liquid-ordered membranes. The disordering was minimal in fluid phase membranes. Interestingly, our results show that the disordering effect of PEtOH in gel phase is sufficiently large to induce phase change at higher PEtOH concentrations. Our results are relevant in the context of natural membranes and could be useful in understanding the role of anesthetics in membrane protein function. PMID:27154601

  15. Sensitive liquid chromatography/tandem mass spectrometry method for the simultaneous determination of nine local anesthetic drugs.

    PubMed

    Tonooka, Keiko; Naruki, Nobuhiko; Honma, Kou; Agei, Kohei; Okutsu, Mayumi; Hosono, Tetsuji; Kunisue, Yoko; Terada, Masaru; Tomobe, Koji; Shinozuka, Tatsuo

    2016-08-01

    A high-performance liquid chromatography-tandem mass spectrometry (LC/MS/MS) with electrospray ionization (ESI) procedure for the simultaneous determination of nine local anesthetic drugs (procaine, mepivacaine, lidocaine, ropivacaine, oxybuprocaine, tetracaine, bupivacaine, T-caine and dibucaine) in human serum is described. The chromatographic separation was performed on a Mightysil-RP-18 GP II column (2.0mm×150mm, particle size 5μm). The mobile phase consisted of 10mM acetic ammonium buffer (pH 5.4) and acetonitrile and was delivered at a flow rate of 0.20mL/min. The triple quadrupole mass spectrometer was operated in positive ion mode, and multiple reaction monitoring was used for drug quantification. Solid-phase extraction of the nine local anesthetic drugs added to the human serum was performed with an Oasis(®) HLB extraction cartridges column. The method was linear for the investigated drugs over the concentration range of 10-100ng/mL. The recoveries of these drugs were in the range of 81.4-144%. The standard deviation (SD) values for all analytes were <0.10 for both intraday and interday accuracy and precision. The selectivity, accuracy and precision of this method are satisfactory for clinical and forensic applications. The sensitive and selective method offers the opportunity for the simultaneous screening and quantification, for clinical and forensic purposes, of almost all local anesthetics available in Japan. PMID:26986505

  16. Local anesthetics induce apoptosis in human thyroid cancer cells through the mitogen-activated protein kinase pathway.

    PubMed

    Chang, Yuan-Ching; Hsu, Yi-Chiung; Liu, Chien-Liang; Huang, Shih-Yuan; Hu, Meng-Chun; Cheng, Shih-Ping

    2014-01-01

    Local anesthetics are frequently used in fine-needle aspiration of thyroid lesions and locoregional control of persistent or recurrent thyroid cancer. Recent evidence suggests that local anesthetics have a broad spectrum of effects including inhibition of cell proliferation and induction of apoptosis in neuronal and other types of cells. In this study, we demonstrated that treatment with lidocaine and bupivacaine resulted in decreased cell viability and colony formation of both 8505C and K1 cells in a dose-dependent manner. Lidocaine and bupivacaine induced apoptosis, and necrosis in high concentrations, as determined by flow cytometry. Lidocaine and bupivacaine caused disruption of mitochondrial membrane potential and release of cytochrome c, accompanied by activation of caspase 3 and 7, PARP cleavage, and induction of a higher ratio of Bax/Bcl-2. Based on microarray and pathway analysis, apoptosis is the prominent transcriptional change common to lidocaine and bupivacaine treatment. Furthermore, lidocaine and bupivacaine attenuated extracellular signal-regulated kinase 1/2 (ERK1/2) activity and induced activation of p38 mitogen-activated protein kinase (MAPK) and c-jun N-terminal kinase. Pharmacological inhibitors of MAPK/ERK kinase and p38 MAPK suppressed caspase 3 activation and PARP cleavage. Taken together, our results for the first time demonstrate the cytotoxic effects of local anesthetics on thyroid cancer cells and implicate the MAPK pathways as an important mechanism. Our findings have potential clinical relevance in that the use of local anesthetics may confer previously unrecognized benefits in the management of patients with thyroid cancer. PMID:24586874

  17. Lipid emulsion-mediated reversal of toxic-dose aminoamide local anesthetic-induced vasodilation in isolated rat aorta

    PubMed Central

    Ok, Seong-Ho; Han, Jeong Yeol; Lee, Soo Hee; Shin, Il-Woo; Lee, Heon Keun; Chung, Young-Kyun; Choi, Mun-Jeoung

    2013-01-01

    Background Intravenous lipid emulsion has been used to treat systemic toxicity of local anesthetics. The goals of this in vitro study were to determine the ability of two lipid emulsions (Intralipid® and Lipofundin® MCT/LCT) to reverse toxic dose local anesthetic-induced vasodilation in isolated rat aortas. Methods Isolated endothelium-denuded aortas were suspended for isometric tension recording. Vasodilation was induced by bupivacaine (3 × 10-4 M), ropivacaine (10-3 M), lidocaine (3 × 10-3 M), or mepivacaine (7 × 10-3 M) after precontraction with 60 mM KCl. Intralipid® and Lipofundin® MCT/LCT were then added to generate concentration-response curves. We also assessed vasoconstriction induced by 60 mM KCl, 60 mM KCl with 3 × 10-4 M bupivacaine, and 60 mM KCl with 3 × 10-4 M bupivacaine plus 1.39% lipid emulsion (Intralipid® or Lipofundin® MCT/LCT). Results The two lipid emulsions reversed vasodilation induced by bupivacaine, ropivacaine, and lidocaine but had no effect on vasodilation induced by mepivacaine. Lipofundin® MCT/LCT was more effective than Intralipid® in reversing bupivacaine-induced vasodilation. The magnitude of lipid emulsion-mediated reversal of vasodilation induced by high-dose local anesthetics was as follows (from highest to lowest): 3 × 10-4 M bupivacaine-induced vasodilation, 10-3 M ropivacaine-induced vasodilation, and 3 × 10-3 M lidocaine-induced vasodilation. Conclusions Lipofundin® MCT/LCT-mediated reversal of bupivacaine-induced vasodilation was greater than that of Intralipid®; however, the two lipid emulsions equally reversed vasodilation induced by ropivacaine and lidocaine. The magnitude of lipid emulsion-mediated reversal of vasodilation appears to be correlated with the lipid solubility of the local anesthetic. PMID:23646246

  18. [Ultrasound-guided peripheral regional anesthesia : placement and dosage of local anesthetics].

    PubMed

    Gorsewski, G; Dinse-Lambracht, A; Tugtekin, I; Gauss, A

    2012-08-01

    Ever since the use of ultrasound guidance in regional anesthesia became more and more popular in recent years, it seemed obvious that so-called intraneural puncture and injection of local anesthetics was much more common than previously assumed. However, neurologic damage was not seen very often. The ultrasound-guided imaging of the nerves showed that intraneural injection has to be seen as an overall term. This term must be characterized in more detail in accordance with nerve anatomy and morphology. Various studies demonstrated that if intraneural puncture occured the needle usually took a path away from the fascicles (intraneural perifascicular), while intraneural transfascicular puncture seemed relatively rare and intraneural intrafascicular placement of the needle even more uncommon. As long as the needle is placed intraneurally but in an extrafascicular fashion a safe injection and the absence of neurologic damage can be assumed. However, if nerve fascicles are affected neurologic dysfunction can occur. In studies investigating the minimal effective local anesthetic volume needed for successful nerve block, a relevant reduction of injected volume was still achieved by intentionally applying the local anesthetic circumferentially around the outermost nerve layer rather than injecting it into neural structures. As an intraneural -intrafascicular injection carries the risk of nerve injury associated with a decrease in quality of life, the potential of ultrasound guidance in regional anesthesia should be considered. Circumferential administration of local anesthetic rather than creating a single point injection appears to be advantageous. PMID:22790475

  19. The Effect and Safety of Steroid Injection in Lumbar Spinal Stenosis: With or Without Local Anesthetics

    PubMed Central

    Song, Sung Hyuk; Ryu, Gi Hyeong; Park, Jin Woo; Lee, Ho Jun; Nam, Ki Yeun; Kim, Hyojun; Kim, Seung Yeon

    2016-01-01

    Objective To compare the long-term effect and safety of an epidural steroid injection in spinal stenosis patients, with or without local anesthetics. Methods Twenty-nine patients diagnosed with spinal stenosis were included and randomly divided into two groups. Translaminar epidural and selective nerve root spinal injection procedures were performed using steroids mixed with local anesthetics or normal saline. The effects of spinal injection procedures were measured with visual analogue scale (VAS) and functional rate index (FRI). These measurements were performed before injection, at 1 month after injection and at 3 months after injection. The occurrence of side effects was investigated each time. Results The VAS and FRI scores were significantly reduced in both the local anesthetics group and normal saline group at 1 and 3 months after the injection. However, there was no significant difference in VAS and FRI score reduction between the two groups each time. Side effects are not noted in both groups. Conclusion The spinal injection procedures using steroids mixed either with local anesthetics or normal saline have an effect in reducing pain and improving functional activities. However, there was no significant difference between the two groups in relation to side effects and the long-term effects of pain and function. PMID:26949664

  20. The local anesthetic tetracaine destabilizes membrane structure by interaction with polar headgroups of phospholipids.

    PubMed

    Shimooka, T; Shibata, A; Terada, H

    1992-03-01

    The effect of the local anesthetic tetracaine at less than 10 mM on the water permeability of the phospholipid membrane was examined using liposomes composed of various molar ratios of negatively charged cardiolipin to electrically neutral phosphatidylcholine by monitoring their osmotic shrinkage in hypertonic glucose solution at 30 degrees C. The concentration of tetracaine causing the maximum velocity of shrinkage of liposomes increased with increase in the molar ratio of cardiolipin. Tetracaine increased the zeta-potential of the negatively charged liposomal membrane toward the positive side due to the binding of its cationic form to the negatively charged polar headgroups in the membrane. The maximum velocity of water permeation induced by osmotic shock was observed at essentially the same tetracaine concentration giving a zeta-potential of the liposomal membrane of 0 mV. These concentrations were not affected by change in the sort of acyl-chain of phospholipids in the liposomes when their negative charges were the same. These results suggests that the membrane integrity is governed mainly by the electrical charge of phospholipid polar headgroups when phospholipid bilayers are in the highly fluid state, and that positively charged tetracaine molecules neutralize the negative surface charge, lowering the barrier for water permeation through phospholipid bilayers. PMID:1547263

  1. Study of the complex formation between amine local anesthetics and uncouplers of oxidative phosphorylation carbonyl cyanide phenylhydrazones.

    PubMed

    Kolajová, M; Antalík, M; Sturdík, E

    1993-06-01

    Spectroscopic evidence is presented which indicates that the anionic uncoupler carbonyl cyanide-4-nitro-2-chloro-phenylhydrazone and the amine local anesthetics form a complex in aqueous solution. The complex formation studies were carried out for several pharmacologically important tertiary amines and some primary amines. Their relative potencies to form a complex with uncoupler have followed the order: procaine < trimecaine < tetracaine < dibucaine < dodecylamine < dicyclohexylamine < hexadecylamine. As to the more lipophilic nature of the complex the emphasized penetration into octanol and reinforced retention into mitochondria was observed. The higher ability of the complex to colapse the mitochondrial membrane potential confirms this fact. The effective concentration of amine local anesthetics to form a complex was correlated with their physicochemical properties namely lipophilicity and acidobasicity. The highest effectivities for complex formation is shown by the most lipophilic and the most ionized molecules of amines. Present results point to the importance of considering the role of amine anesthetic-uncoupler complex in interpreting physiological or ion transport data in which these substances have been used together. PMID:8224779

  2. [Pregnancy and lactation period: Which local anesthetics and analgesics?].

    PubMed

    Fatori Popovic, Sandra; Lübbers, Heinz-Theo; von Mandach, Ursula

    2016-01-01

    The aim of this paper is to show relevant aspects of dental treatment in pregnancy. Common medication used in dental offices should be highlighted in special regard to the pregnant patient during dental treatment. The reader should gain more security in the election of the proper drugs for local anesthesia and oral analgesics. Local anaesthetics such as articain with adrenalin in a dilution of 1 : 200 000 can be used for dental treatment at any time. Paracetamol should be used as first line oral analgesic. Elective dental procedures should be postponed after delivery and after lactation period. PMID:27142442

  3. Bupivacaine versus lignocaine as the choice of locall anesthetic agent for impacted third molar surgery a review

    PubMed Central

    Balakrishnan, K.; Ebenezer, Vijay; Dakir, Abu; Kumar, Saravana; Prakash, D.

    2015-01-01

    One of the most important goal in minor surgical procedures is to achieve proper and sufficient anesthesia and analgesia preoperatively, intraoperatively and in the immediate postoperative period. Several local anesthetic agents have been cited in the literature and studied. Bupivacaine is one of the most common long-acting anesthetic agents being used for surgical removal of impacted third molars. Lignocaine is one of the commonest short-acting anesthetic agents being used for the same procedure. In this review article, the analgesic and anesthetic abilities of the bupivacaine versus lignocaine have been reviewed while surgical removal of impacted third molars. PMID:26015720

  4. The effect of local anesthetic on pro-inflammatory macrophage modulation by mesenchymal stromal cells.

    PubMed

    Gray, Andrea; Marrero-Berrios, Ileana; Weinberg, Jonathan; Manchikalapati, Devasena; SchianodiCola, Joseph; Schloss, Rene S; Yarmush, Joel

    2016-04-01

    Administering local anesthetics (LAs) peri- and post-operatively aims to prevent or mitigate pain in surgical procedures and after tissue injury in cases of osteoarthritis (OA) and other degenerative diseases. Innovative tissue protective and reparative therapeutic interventions such as mesenchymal stromal cells (MSCs) are likely to be exposed to co-administered drugs such as LAs. Therefore, it is important to determine how this exposure affects the therapeutic functions of MSCs and other cells in their target microenvironment. In these studies, we measured the effect of LAs, lidocaine and bupivacaine, on macrophage viability and pro-inflammatory secretion. We also examined their effect on modulation of the macrophage pro-inflammatory phenotype in an in vitro co-culture system with MSCs, by quantifying macrophage tumor necrosis factor (TNF)-α secretion and MSC prostaglandin E2 (PGE2) production. Our studies indicate that both LAs directly attenuated macrophage TNF-α secretion, without significantly affecting viability, in a concentration- and potency-dependent manner. LA-mediated attenuation of macrophage TNF-α was sustained in co-culture with MSCs, but MSCs did not further enhance this anti-inflammatory effect. Concentration- and potency-dependent reductions in macrophage TNF-α were concurrent with decreased PGE2 levels in the co-cultures further indicating MSC-independent macrophage attenuation. MSC functional recovery from LA exposure was assessed by pre-treating MSCs with LAs prior to co-culture with macrophages. Both MSC attenuation of TNF-α and PGE2 secretion were impaired by pre-exposure to the more potent bupivacaine and high dose of lidocaine in a concentration-dependent manner. Therefore, LAs can affect anti-inflammatory function by both directly attenuating macrophage inflammation and MSC secretion and possibly by altering the local microenvironment which can secondarily reduce MSC function. Furthermore, the LA effect on MSC function may persist

  5. [Use of local anesthetics in dentistry: medico-legal aspects].

    PubMed

    Martini, P; Fineschi, V

    1990-01-01

    The Authors consider the problem of the clinical use of local anaesthetics in dentistry with a view to establishing possible adverse reactions, of which they provide a schematic analysis and an up to date pathogenetic survey; they thus make their observations on case historics taken from the sector of forensic medicine in Siena, and in conclusion make a jurisprudential digression in the form of a discussion on the responsibility of the practitioner in the strait of anaesthesiology, emphasizing by the same, an ever increasingly harmonizing evolution with regular judicial procedure in common law countries. PMID:2079235

  6. Subunit and frequency-dependent inhibition of Acid Sensing Ion Channels by local anesthetic tetracaine

    PubMed Central

    2013-01-01

    Background Extracellular acidosis is a prominent feature of multiple pathological conditions, correlating with pain sensation. Acid-sensing ion channels (ASICs), a family of proton-gated cation channels, are distributed throughout the central and peripheral nervous systems. Activation of ASICs, particularly ASIC3 and ASIC1a channels, by acidic pH and the resultant depolarization of nociceptive primary sensory neurons, participates in nociception. Agents that inhibit the activation of ASICs are thus expected to be analgesic. Here, we studied the effect of local anesthetic tetracaine on ASIC currents. Results Tetracaine inhibited the peak ASIC3 current in a concentration-dependent manner with an IC50 of 9.96 ± 1.88 mM. The degree of inhibition by tetracaine was dependent on the extracellular pH but independent of the membrane potential. Furthermore, 3 mM tetracaine also inhibited 29.83% of the sustained ASIC3 current. In addition to ASIC3, tetracaine inhibited the ASIC1a and ASIC1β currents. The inhibition of the ASIC1a current was influenced by the frequency of channel activation. In contrast to ASIC3, ASIC1a, and ASIC1β currents, ASIC2a current was not inhibited by tetracaine. In cultured mouse dorsal root ganglion neurons, 1–3 mM tetracaine inhibited both the transient and sustained ASIC currents. At pH4.5, 3 mM tetracaine reduced the peak ASIC current to 60.06 ± 4.51%, and the sustained current to 48.24 ± 7.02% of the control values in dorsal root ganglion neurons. In contrast to ASICs, voltage-gated sodium channels were inhibited by acid, with 55.15% inhibition at pH6.0 and complete inhibition at pH5.0. Conclusions These findings disclose a potential new mechanism underlying the analgesic effects of local anesthetics, particularly in acidic conditions where their primary target (i.e. voltage-gated Na+ channel) has been suppressed by protons. PMID:23758830

  7. 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. PMID:19245753

  8. Actions of Bupivacaine, a Widely Used Local Anesthetic, on NMDA Receptor Responses

    PubMed Central

    Paganelli, Meaghan A.

    2015-01-01

    NMDA receptors mediate excitatory neurotransmission in brain and spinal cord and play a pivotal role in the neurological disease state of chronic pain, which is caused by central sensitization. Bupivacaine is the indicated local anesthetic in caudal, epidural, and spinal anesthesia and is widely used clinically to manage acute and chronic pain. In addition to blocking Na+ channels, bupivacaine affects the activity of many other channels, including NMDA receptors. Importantly, bupivacaine inhibits NMDA receptor-mediated synaptic transmission in the dorsal horn of the spinal cord, an area critically involved in central sensitization. We used recombinant NMDA receptors expressed in HEK293 cells and found that increasing concentrations of bupivacaine decreased channel open probability in GluN2 subunit- and pH-independent manner by increasing the mean duration of closures and decreasing the mean duration of openings. Using kinetic modeling of one-channel currents, we attributed the observed current decrease to two main mechanisms: a voltage-dependent “foot-in-the-door” pore block and an allosteric gating effect. Further, the inhibition was state-independent because it occurred to the same degree whether the drug was applied before or after glutamate stimulation and was mediated by extracellular and intracellular inhibitory sites, via hydrophilic and hydrophobic pathways. These results predict that clinical doses of bupivacaine would decrease the peak and accelerate the decay of synaptic NMDA receptor currents during normal synaptic transmission. These quantitative predictions inform possible applications of bupivacaine as preventative and therapeutic approaches in chronic pain. PMID:25589775

  9. The Diagnosis of the Os Trigonum Syndrome with a Fluoroscopically Controlled Injection of Local Anesthetic

    PubMed Central

    Jones, Darron M; Saltzman, Charles L; El-Khoury, George

    1999-01-01

    Purpose To report the results of excision of the os trigonum using a fluoroscopically controlled injection of local anesthetic to diagnose the os trigonum syndrome. Design and patients Os trigonum syndrome is a recognized cause of pain in the posterior aspect of the foot and ankle. The symptoms and physical findings, however, are often nonspecific and difficult to differentiate from other causes of posterior ankle pain. We report four patients with persistent posterolateral ankle pain despite prolonged nonoperative treatment. An os trigonal syndrome was diagnosed by a positive response to a fluoroscopically guided local anesthetic injection in the region of synchondrosis between the os trigonum and the posterior talus. Results All four patients underwent excision of the os trigonum with complete resolution of symptoms and return to full activity. Conclusions Fluoroscopically controlled injection can help confirm the suspected diagnosis of an os trigonum syndrome and may have positive predictive value regarding the outcome of excisional surgery. PMID:10847526

  10. In vivo comparison of the reinforcing and dopamine transporter effects of local anesthetics in rhesus monkeys.

    PubMed

    Wilcox, Kristin M; Kimmel, Heather L; Lindsey, Kimberly P; Votaw, John R; Goodman, Mark M; Howell, Leonard L

    2005-12-15

    Dopaminergic mechanisms are thought to play a central role in the reinforcing effects of cocaine. Similar to cocaine, other local anesthetics bind to the dopamine transporter (DAT) and inhibit DA uptake in rodent and monkey brain. Additionally, local anesthetics are self-administered in rhesus monkeys, indicative of abuse liability. The present study examined the reinforcing and DAT effects of the local anesthetics dimethocaine, procaine and cocaine using in vivo techniques. Monkeys were trained to respond under a second-order schedule for i.v. cocaine administration (0.10 or 0.30 mg/kg/infusion). When responding was stable, dimethocaine (0.030-1.7 mg/kg/ infusion) or procaine (0.10-10 mg/kg/ infusion) was substituted for the cocaine training dose. Dimethocaine administration produced higher response rates compared with that of procaine, and was a more potent reinforcer. Drug effects on behavior were related to DAT occupancy in monkey striatum during neuroimaging with positron emission tomography (PET). DAT occupancy was determined by displacement of 8-(2-[(18)F]fluroethyl)2beta-carbomethoxy-3beta-(4-chlorophenyl)nortropane (FECNT). DAT occupancy was between 66 and 82% and <10-41% for doses of dimethocaine and procaine that maintained maximum response rates, respectively. Finally, in vivo microdialysis in awake subjects determined drug-induced changes in extracellular DA in the caudate nucleus. There was close correspondence between peak increases in DA and DAT occupancy. Overall, reinforcing effects were consistent with DAT effects determined with in vivo techniques. The results further support a role for the DAT in the abuse liability of local anesthetics. PMID:16206183

  11. Efficacy of epidural local anesthetic and dexamethasone in providing postoperative analgesia: A meta-analysis

    PubMed Central

    Jebaraj, B; Khanna, P; Baidya, DK; Maitra, S

    2016-01-01

    Background: Dexamethasone is a potent anti-inflammatory, analgesic, and antiemetic drug. Individual randomized controlled trials found a possible benefit of epidural dexamethasone. The purpose of this meta-analysis is to estimate the benefit of epidural dexamethasone on postoperative pain and opioid consumption and to formulate a recommendation for evidence-based practice. Materials and Methods: Prospective, randomized controlled trials comparing the analgesic efficacy of epidural local anesthetic and dexamethasone combination, with local anesthetic alone for postoperative pain management after abdominal surgery, were planned to be included in this meta-analysis. PubMed, PubMed Central, Scopus, and Central Register of Clinical Trials of the Cochrane Collaboration (CENTRAL) databases were searched for eligible controlled trials using the following search words: “Epidural”, “dexamethasone”, and “postoperative pain”, until February 20, 2015. Results: Data from five randomized control trials have been included in this meta-analysis. Epidural dexamethasone significantly decreased postoperative morphine consumption (mean difference −7.89 mg; 95% confidence interval [CI]: −11.66 to −3.71) and number of patients required postoperative rescue analgesic boluses (risk ratio: 0.51; 95% CI: 0.41-0.63). Conclusion: The present data shows that the addition of dexamethasone to local anesthetic in epidural is beneficial for postoperative pain management. PMID:27375389

  12. High-field localized 1H NMR spectroscopy in the anesthetized and in the awake monkey.

    PubMed

    Pfeuffer, Josef; Juchem, Christoph; Merkle, Hellmut; Nauerth, Arno; Logothetis, Nikos K

    2004-12-01

    Localized cerebral in vivo 1H NMR spectroscopy (MRS) was performed in the anesthetized as well as the awake monkey using a novel vertical 7 T/60 cm MR system. The increased sensitivity and spectral dispersion gained at high field enabled the quantification of up to 16 metabolites in 0.1- to 1-ml volumes. Quantification was accomplished by using simulations of 18 metabolite spectra and a macromolecule (MM) background spectrum consisting of 12 components. Major cerebral metabolites (concentrations >3 mM) such as glutamate (Glu), N-acetylaspartate (NAA), creatine (Cr)/phosphocreatine (PCr) and myo-inositol (Ins) were identified with an error below 3%; most other metabolites were quantified with errors in the order of 10%. Metabolite ratios were 1.39:1 for total NAA, 1.38:1 for glutamate (Glu)/glutamine (Gln) and 0.09:1 for cholines (Cho) relative to total Cr. Taurine (Tau) was detectable at concentrations lower than 1 mM, while lactate (Lac) remained below the detection limit. The spectral dispersion was sufficient to separate metabolites of similar spectral patterns, such as Gln and Glu, N-acetylaspartylglutamate (NAAG) and NAA, and PCr-Cr. MRS in the awake monkey required the development and refinement of acquisition and correction strategies to minimize magnetic susceptibility artifacts induced by respiration and movement of the mouth or body. Periods with major motion artifacts were rejected, while a frequency/phase correction was performed on the remaining single spectra before averaging. In resting periods, both spectral amplitude and line width, that is, the voxel shim, were unaffected permitting reliable measurements. The corrected spectra obtained from the awake monkey afforded the reliable detection of 6-10 cerebral metabolites of 1-ml volumes. PMID:15707786

  13. Adjuvants to prolong the local anesthetic effects of coated microneedle products.

    PubMed

    Zhang, Ying; Siebenaler, Kris; Brown, Ken; Dohmeier, Daniel; Hansen, Kris

    2012-12-15

    The objective of this study was to identify an adjuvant for anesthetics coated on microneedles to provide rapid onset and prolonged analgesic action with minimal skin tissue reaction. Aqueous lidocaine or prilocaine formulations with or without clonidine or the related analogs, guanfacine and apraclonidine, were dip-coated onto polymeric microneedles. The amount of lidocaine or prilocaine coated onto the microneedles was assessed by high performance liquid chromatography (HPLC). Delivery efficiency and dermal pharmacokinetics associated with lidocaine or prilocaine delivered via the microneedles were characterized in vivo using domestic swine. Skin punch biopsies were collected and analyzed to determine the anesthetic concentrations in the skin using HPLC-mass spectrometry (LC-MS). Addition of clonidine to the formulations decreased the systemic absorption rate of the anesthetics from the patch application site without impacting the coating performance or the rapid onset of anesthesia. Formulations with 0.3 wt.% clonidine, identified as the optimal dose for lidocaine-delivery via microneedles, maintained the lidocaine skin concentration above the estimated therapeutic level (100 ng/mg) for 1 h without causing any skin irritation or color change. The other two clonidine analogs, guanfacine and apraclonidine, also led to delayed systemic absorption of lidocaine from the skin, indicating utility in providing prolonged analgesia. PMID:23022295

  14. Minimally Painful Local Anesthetic Injection for Cleft Lip/Nasal Repair in Grown Patients

    PubMed Central

    Price, Christopher; Wong, Alison L.; Chokotho, Tilinde

    2014-01-01

    Introduction: There has been a recent interest in injecting large body and face areas with local anesthetic in a minimally painful manner. The method includes adherence to minimal pain injection details as well feedback from the patient who counts the number of times he feels pain during the injection process. This article describes the successes and limitations of this technique as applied to primary cleft lip/nasal repair in grown patients. Methods: Thirty-two primary cleft lip patients were injected with local anesthesia by 3 surgeons and then underwent surgical correction of their deformity. At the beginning of the injection of the local anesthetic, patients were instructed to clearly inform the injector each and every time they felt pain during the entire injection process. Results: The average patient felt pain only 1.6 times during the injection process. This included the first sting of the first 27-gauge needle poke. The only pain that 51% of the patients felt was that first poke of the first needle; 24% of the patients only felt pain twice during the whole injection process. The worst pain score occurred in a patient who felt pain 6 times during the injection process. Ninety-one percent of the patients felt no pain at all after the injection of the local anesthetic and did not require a top-up. Conclusion: It is possible to successfully and reliably inject local anesthesia in a minimally painful manner for cleft lip and nasal repair in the fully grown cleft patient. PMID:25289364

  15. Influence of the local anesthetic tetracaine on the phase behavior and the thermodynamic properties of phospholipid bilayers.

    PubMed Central

    Böttner, M; Winter, R

    1993-01-01

    We investigated the influence of the local anesthetic tetracaine on the thermodynamic properties and the temperature- and pressure-dependent phase behavior of the model biomembrane 1,2-dimyristoyl-sn-glycero-3-phosphocholine by using volumetric measurements at temperatures ranging from 0 degrees to 40 degrees C and at pressures from ambient up to 1000 bar. The pVT measurements were complemented by temperature-dependent differential scanning calorimetric measurements. Information about the influence of different concentrations of the local anesthetic on the thermodynamic changes accompanying the lipid phase transitions, and on the thermal expansion coefficient, the isothermal compressibility, and the volume fluctuations of the lipids in their different phases, could be obtained from these experiments. The incorporation of tetracaine leads to an overall disordering of the membrane, as can be inferred from the depression of the main transition temperature and the reduction of the volume change at the main lipid phase transition. The expansion coefficient alpha p and the isothermal compressibility chi T of the lipid bilayer are enhanced by the addition of tetracaine and strongly enhanced values of alpha p and chi T, and the lipid volume fluctuations are found in the direct neighborhood of the main phase transition region. As tetracaine can be viewed as a model system for amphiphilic molecules, these results also provide insight into the general understanding of the physicochemical action of amphiphilic molecules on membranes. The experimental results are compared with recent theoretical predictions for the phase behavior of anesthetic-lipid systems, and the biological relevance of this study is discussed. PMID:8298033

  16. Effect of needle design on pain from dental local anesthetic injections.

    PubMed

    McPherson, Joanna Saenz; Dixon, Sara A; Townsend, Richard; Vandewalle, Kraig S

    2015-01-01

    The purpose of this randomized, double-blind clinical study was to evaluate the effectiveness of a larger-bore compared with a standard-bore dental local anesthetic needle of the same gauge in reducing pain during inferior alveolar (IA) and long buccal (LB) nerve block injections. Twenty active duty military or Department of Defense beneficiaries undergoing dental treatment were anesthetized using a split-mouth design with 4 anesthetic dental injections. Both sides of the mouth received IA nerve block and LB nerve injections, one using the 27-gauge large-bore Septoject XL needle and other using a 27-gauge standard-bore Septoject needle. Patients rated the pain experienced with each method using a visual analogue scale (VAS). The IA injection mean VAS score and standard deviation were 38.9 ± 22.7 mm and 37.1 ± 22.4 mm, respectively, for the larger and standard-bore needles. The LB injection mean VAS score and standard deviation were 33.5 ± 22.8 mm and 35.1 ± 19.6 mm, respectively, for the larger and standard-bore needles. The data were analyzed with a paired t test (α = .05). No significant difference was found between the IA (P = .70) or LB injections (P = .73). The use of a larger-bore 27-gauge needle did not reduce pain on injection compared with the standard-bore 27-gauge needle. PMID:25849467

  17. Effect of Needle Design on Pain From Dental Local Anesthetic Injections

    PubMed Central

    McPherson, Joanna Saenz; Dixon, Sara A.; Townsend, Richard; Vandewalle, Kraig S.

    2015-01-01

    The purpose of this randomized, double-blind clinical study was to evaluate the effectiveness of a larger-bore compared with a standard-bore dental local anesthetic needle of the same gauge in reducing pain during inferior alveolar (IA) and long buccal (LB) nerve block injections. Twenty active duty military or Department of Defense beneficiaries undergoing dental treatment were anesthetized using a split-mouth design with 4 anesthetic dental injections. Both sides of the mouth received IA nerve block and LB nerve injections, one using the 27-gauge large-bore Septoject XL needle and other using a 27-gauge standard-bore Septoject needle. Patients rated the pain experienced with each method using a visual analogue scale (VAS). The IA injection mean VAS score and standard deviation were 38.9 ± 22.7 mm and 37.1 ± 22.4 mm, respectively, for the larger and standard-bore needles. The LB injection mean VAS score and standard deviation were 33.5 ± 22.8 mm and 35.1 ± 19.6 mm, respectively, for the larger and standard-bore needles. The data were analyzed with a paired t test (α = .05). No significant difference was found between the IA (P = .70) or LB injections (P = .73). The use of a larger-bore 27-gauge needle did not reduce pain on injection compared with the standard-bore 27-gauge needle. PMID:25849467

  18. Assessing Changes in Volatile General Anesthetic Sensitivity of Mice after Local or Systemic Pharmacological Intervention

    PubMed Central

    McCarren, Hilary S.; Moore, Jason T.; Kelz, Max B.

    2013-01-01

    One desirable endpoint of general anesthesia is the state of unconsciousness, also known as hypnosis. Defining the hypnotic state in animals is less straightforward than it is in human patients. A widely used behavioral surrogate for hypnosis in rodents is the loss of righting reflex (LORR), or the point at which the animal no longer responds to their innate instinct to avoid the vulnerability of dorsal recumbency. We have developed a system to assess LORR in 24 mice simultaneously while carefully controlling for potential confounds, including temperature fluctuations and varying gas flows. These chambers permit reliable assessment of anesthetic sensitivity as measured by latency to return of the righting reflex (RORR) following a fixed anesthetic exposure. Alternatively, using stepwise increases (or decreases) in anesthetic concentration, the chambers also enable determination of a population's sensitivity to induction (or emergence) as measured by EC50 and Hill slope. Finally, the controlled environmental chambers described here can be adapted for a variety of alternative uses, including inhaled delivery of other drugs, toxicology studies, and simultaneous real-time monitoring of vital signs. PMID:24192721

  19. Assessing changes in volatile general anesthetic sensitivity of mice after local or systemic pharmacological intervention.

    PubMed

    McCarren, Hilary S; Moore, Jason T; Kelz, Max B

    2013-01-01

    One desirable endpoint of general anesthesia is the state of unconsciousness, also known as hypnosis. Defining the hypnotic state in animals is less straightforward than it is in human patients. A widely used behavioral surrogate for hypnosis in rodents is the loss of righting reflex (LORR), or the point at which the animal no longer responds to their innate instinct to avoid the vulnerability of dorsal recumbency. We have developed a system to assess LORR in 24 mice simultaneously while carefully controlling for potential confounds, including temperature fluctuations and varying gas flows. These chambers permit reliable assessment of anesthetic sensitivity as measured by latency to return of the righting reflex (RORR) following a fixed anesthetic exposure. Alternatively, using stepwise increases (or decreases) in anesthetic concentration, the chambers also enable determination of a population's sensitivity to induction (or emergence) as measured by EC50 and Hill slope. Finally, the controlled environmental chambers described here can be adapted for a variety of alternative uses, including inhaled delivery of other drugs, toxicology studies, and simultaneous real-time monitoring of vital signs. PMID:24192721

  20. Ventilatory response to high inspired carbon dioxide concentrations in anesthetized dogs

    PubMed Central

    Loeppky, Jack A.; Risling, Ray

    2011-01-01

    Background: The ventilation ( ) response to inspired CO2 has been extensively studied, but rarely with concentrations >10%. Aims: These experiments were performed to determine whether would increase correspondingly to higher concentrations and according to conventional chemoreceptor time delays. Materials and Methods: We exposed anesthetized dogs acutely, with and without vagotomy and electrical stimulation of the right vagus, to 20-100% CO2-balance O2 and to 0 and 10% O2-balance N2. Results: The time delays decreased and response magnitude increased with increasing concentrations (p<0.01), but at higher concentrations the time delays were shorter than expected, i.e., 0.5 s to double at 100% CO2, with the response to 0% O2 being ~3 s slower. Right vagotomy significantly reduced baseline breathing frequency (fR), increased tidal volume (VT) and increased the time delay by ~3 s. Bilateral vagotomy further reduced baseline fR and , and reduced the response to CO2 and increased the time delay by ~12 s. Electro-stimulation of the peripheral right vagus while inspiring CO2 caused a 13 s asystole and further reduced and delayed the response, especially after bilateral vagotomy, shifting the mode from VT to fR. Conclusions: Results indicate that airway or lung receptors responded to the rapid increase in lung H+ and that vagal afferents and unimpaired circulation seem necessary for the initial rapid response to high CO2 concentrations by receptors upstream from the aortic bodies. PMID:22540067

  1. Mutant bacterial sodium channels as models for local anesthetic block of eukaryotic proteins.

    PubMed

    Smith, Natalie E; Corry, Ben

    2016-05-01

    Voltage gated sodium channels are the target of a range of local anesthetic, anti-epileptic and anti-arrhythmic compounds. But, gaining a molecular level understanding of their mode of action is difficult as we only have atomic resolution structures of bacterial sodium channels not their eukaryotic counterparts. In this study we used molecular dynamics simulations to demonstrate that the binding sites of both the local anesthetic benzocaine and the anti-epileptic phenytoin to the bacterial sodium channel NavAb can be altered significantly by the introduction of point mutations. Free energy techniques were applied to show that increased aromaticity in the pore of the channel, used to emulate the aromatic residues observed in eukaryotic Nav1.2, led to changes in the location of binding and dissociation constants of each drug relative to wild type NavAb. Further, binding locations and dissociation constants obtained for both benzocaine (660 μM) and phenytoin (1 μ M) in the mutant channels were within the range expected from experimental values obtained from drug binding to eukaryotic sodium channels, indicating that these mutant NavAb may be a better model for drug binding to eukaryotic channels than the wild type. PMID:26852716

  2. Effects of tertiary amine local anesthetics on the assembly and disassembly of brain microtubules in vitro.

    PubMed

    Genna, J M; Coffe, G; Pudles, J

    1980-09-01

    From kinetic and electron microscopy studies on the effects of procaine, tetracaine and dibucaine on the polymerization and depolymerization of the microtubules isolated from pig and rat brains the following results were obtained. 1. Procaine or tetracaine, at the concentration range of 0.5--20 mM and of 0.5--5 mM respectively, increases the rate of tubulin polymerization (24 degrees C or 37 degrees C) and of microtubule depolymerization (4 degrees C) as a linear function of the concentration of the anesthetics, while identical amounts of microtubules are formed. In the absence of microtubule-associated proteins the polymerization of tubulin is not induced by 10 mM procaine, furthermore, the critical concentration of microtubule proteins necessary for assembly into microtubules is not affected at this concentration level of the anesthetic. This suggests that procaine affects not the nucleation, but rather the elongation process. 2. Dibucaine, from 0.5 mM to 3 mM increases the lag time of the polymerization reaction, while from 0.5 mM to 2 mM it linearly decreases both tubulin polymerization (24 degrees C) and microtubule depolymerization (4 degrees C) rates. Dibucaine, up to mM concentration, does not affect the extent of tubulin polymerization; however, above this concentration it induces the formation of amorphous aggregates. 3. Procaine or tetracaine enhances the depolymerizing effect of calcium on microtubules. The half-maximal values for the depolymerizing effect of calcium were 0.96, 0.71 and 0.51 mM for the control, in the presence of 10 mM procaine and 5 mM tetracaine respectively. PMID:7439170

  3. Local anesthetic effects of cocaine and several extracts of the coca leaf (E. coca).

    PubMed

    Bedford, J A; Turner, C E; Elsohly, H N

    1984-05-01

    Cocaine and a number of different fractions of a crude ethanol extract of the coca leaf (E. coca) were subjected to a local anesthetic screen using rat tail withdrawal from electric shock. Following an intradermal injection of 0.1 ml of a 2.0% (w.v) solution of cocaine HCl, an immediate response was observed. Two of the coca fractions also produced some local anesthesia. An alkaloidal fraction, containing an equivalent amount of cocaine, produced a maximum effect that was approximately 20% less than that observed with cocaine. The only other fraction producing any effect, a water soluble cocaine-free fraction, showed a maximum response that was approximately 30% of that observed with cocaine. PMID:6739520

  4. Simultaneous determination of four local anesthetics by CE with ECL and study on interaction between procainamide and human serum albumin.

    PubMed

    Duan, Hong-Bing; Cao, Jun-Tao; Yang, Jiu-Jun; Wang, Hui; Liu, Yan-Ming

    2016-07-01

    A new method of capillary electrophoresis (CE) coupled with tris(2, 2'-bipyridyl) ruthenium(II) electrochemiluminescence (ECL) detection has been developed to detect four local anesthetics procainamide (PAH), tetracaine (TCH), proparacaine (PCH) and cinchocaine (CIN) simultaneously. An europium (III)-doped prussian blue analogue film (Eu-PB) modified platinum electrode was prepared and applied to improve the detection sensitivity. The parameters including additives, concentration and pH of the running buffer, separation voltage and detection potential that affect CE separation and ECL detection were optimized in detail. The four local anesthetics were baseline separated and detected within 10min under the optimized conditions. The detection limits (LOD) of PAH, TCH, PCH and CIN are 5.5×10(-8), 9.6×10(-8), 2.5×10(-8) and 3.5×10(-8)molL(-1) (S/N=3), respectively. RSDs of the migration time for four analytes range from 1.2% to 2.5% within intraday and from 2.4% to 4.9% in interday, RSDs of the peak area for four analytes are from 1.7% to 3.3% within intraday and from 2.2% to 5.6% in interday, respectively. The limits of quantitation (LOQ) (S/N=10) for PAH, TCH, PCH and CIN in human urine sample are 5.9×10(-7), 9.2×10(-7), 8.3×10(-7) and 5.0×10(-7)molL(-1), separately. The recoveries (n=3) of four analytes in human urine are from 87.6% to 107.7% with less than 5.9% in RSDs. The developed method was used to determine four local anesthetics in human urine samples and investigate the interaction between PAH and human serum albumin (HSA). The number of binding sites and the binding constant of PAH with HSA were calculated to be 1.03 and 2.4×10(4)Lmol(-1), respectively. PMID:27154684

  5. Is transverse abdominis plane block effective following local anesthetic infiltration in laparoscopic totally extraperitoneal hernia repair?

    PubMed Central

    Kim, Mun Gyu; Ok, Si Young; Kim, Sang Ho; Lee, Se-Jin; Park, Sun Young; Yoo, Jae-Hwa; Cho, Ana; Hur, Kyung Yul; Kim, Myung Jin

    2014-01-01

    Background Transverse abdominis plane (TAP) block can be recommended as a multimodal method to reduce postoperative pain in laparoscopic abdominal surgery. However, it is unclear whether TAP block following local anesthetic infiltration is effective. We planned this study to evaluate the effectiveness of the latter technique in laparoscopic totally extraperitoneal hernia repair (TEP). Methods We randomly divided patients into two groups: the control group (n = 37) and TAP group (n = 37). Following the induction of general anesthesia, as a preemptive method, all of the patients were subjected to local anesthetic infiltration at the trocar sites, and the TAP group was subjected to ultrasound-guided bilateral TAP block with 30 ml of 0.375% ropivacaine in addition before TEP. Pain was assessed in the recovery room and post-surgery at 4, 8, and 24 h. Additionally, during the postoperative 24 h, the total injected dose of analgesics and incidence of nausea were recorded. Results: On arrival in the recovery room, the pain score of the TAP group (4.33 ± 1.83) was found to be significantly lower than that of the control group (5.73 ± 2.04). However, the pain score was not significantly different between the TAP group and control group at 4, 8, and 24 h post-surgery. The total amounts of analgesics used in the TAP group were significantly less than in the control group. No significant difference was found in the incidence of nausea between the two groups. Conclusions TAP block following local infiltration had a clinical advantage only in the recovery room. PMID:25558340

  6. Dissociation of the vacuolar and macroautophagic cytopathology from the cytotoxicity induced by the lipophilic local anesthetic bupivacaine.

    PubMed

    Morissette, Guillaume; Bawolak, Marie-Thérèse; Marceau, François

    2011-07-01

    Local anesthetics, like many other cationic drugs, induce a vacuolar and macroautophagic cytopathology that has been observed in vivo and in various cell types; some also induce cytotoxicity of mitochondrial origin (apoptosis and necrosis) and it is not known whether the 2 types of toxicity overlap or interact. We compared bupivacaine with a more hydrophilic agent, lidocaine, for morphological, functional, and toxicological responses in a previously exploited nonneuronal system, primary smooth muscle cells. Bupivacaine induced little vacuolization (≥2.5 mmol/L, 4 h), but elicited autophagic accumulation (≥0.5 mmol/L, 4 h) and was massively cytotoxic at 2.5-5 mmol/L (4-24 h), the latter effect being unabated by the V-ATPase inhibitor bafilomycin A1. Lidocaine exerted little cytotoxicity at and below 5 mmol/L for 24 h, but intensely induced the V-ATPase-dependent vacuolar and autophagic cytopathology. Bupivacaine was more potent than lidocaine in disrupting mitochondrial potential, as judged by Mitotracker staining (significant proportions of cells affected in the 1-5 and 5-10 mmol/L concentration ranges, respectively). The addition of mitochondrial-inactivating toxins antimycin A and oligomycin to lidocaine (2.5 mmol/L) reproduced the profile of bupivacaine action (low intensity of vacuolization and retained autophagic accumulation). The high potency of bupivacaine as a mitochondrial toxicant eclipses the benign vacuolar and autophagic response seen with more hydrophilic local anesthetics. PMID:21812528

  7. Local anesthetic infusion pumps improve postoperative pain after inguinal hernia repair: a randomized trial.

    PubMed

    Sanchez, Barry; Waxman, Kenneth; Tatevossian, Raymond; Gamberdella, Marla; Read, Bruce

    2004-11-01

    Pain after an open inguinal hernia repair may be significant. In fact, some surgeons feel that the pain after open repair justifies a laparoscopic approach. The purpose of this study was to determine if the use of local anesthetic infusion pumps would reduce postoperative pain after open inguinal hernia repair. We performed a prospective, double-blind randomized study of 45 open plug and patch inguinal hernia repairs. Patients were randomized to receive either 0.25 per cent bupivicaine or saline solution via an elastomeric infusion pump (ON-Q) for 48 hours, at 2 cc/h. The catheters were placed in the subcutaneous tissue and removed on postoperative day 3. Both groups were prescribed hydrocodone to use in the postoperative period at the prescribed dosage as needed for pain. Interviews were conducted on postoperative days 3 and 7, and patient's questionnaires, including pain scores, amount of pain medicine used, and any complications, were collected accordingly. During the first 5 postoperative days, postoperative pain was assessed using a visual analog scale. Twenty-three repairs were randomized to the bupivicaine group and 22 repairs randomized to the placebo group. In the bupivicaine group, there was a significant decrease in postoperative pain on postoperative days 2 through 5 with P values <0.05. This significant difference continued through postoperative day 5, 2 days after the infusion pumps were removed. Patients who had bupivicaine instilled in their infusion pump had statistically significant lower subjective pain scores on postoperative days 2 through 5. This significant difference continued even after the infusion pumps were removed. Local anesthetic infusion pumps significantly decreased the amount of early postoperative pain. Pain relief persisted for 2 days after catheter and pump removal. PMID:15586515

  8. Local Anesthetic Peripheral Nerve Block Adjuvants for Prolongation of Analgesia: A Systematic Qualitative Review

    PubMed Central

    Kirksey, Meghan A.; Haskins, Stephen C.; Cheng, Jennifer; Liu, Spencer S.

    2015-01-01

    Background The use of peripheral nerve blocks for anesthesia and postoperative analgesia has increased significantly in recent years. Adjuvants are frequently added to local anesthetics to prolong analgesia following peripheral nerve blockade. Numerous randomized controlled trials and meta-analyses have examined the pros and cons of the use of various individual adjuvants. Objectives To systematically review adjuvant-related randomized controlled trials and meta-analyses and provide clinical recommendations for the use of adjuvants in peripheral nerve blocks. Methods Randomized controlled trials and meta-analyses that were published between 1990 and 2014 were included in the initial bibliographic search, which was conducted using Medline/PubMed, Cochrane Central Register of Controlled Trials, and EMBASE. Only studies that were published in English and listed block analgesic duration as an outcome were included. Trials that had already been published in the identified meta-analyses and included adjuvants not in widespread use and published without an Investigational New Drug application or equivalent status were excluded. Results Sixty one novel clinical trials and meta-analyses were identified and included in this review. The clinical trials reported analgesic duration data for the following adjuvants: buprenorphine (6), morphine (6), fentanyl (10), epinephrine (3), clonidine (7), dexmedetomidine (7), dexamethasone (7), tramadol (8), and magnesium (4). Studies of perineural buprenorphine, clonidine, dexamethasone, dexmedetomidine, and magnesium most consistently demonstrated prolongation of peripheral nerve blocks. Conclusions Buprenorphine, clonidine, dexamethasone, magnesium, and dexmedetomidine are promising agents for use in prolongation of local anesthetic peripheral nerve blocks, and further studies of safety and efficacy are merited. However, caution is recommended with use of any perineural adjuvant, as none have Food and Drug Administration approval, and

  9. Use of continuous local anesthetic infusion in the management of postoperative split-thickness skin graft donor site pain.

    PubMed

    Hernandez, Jorge L Reguero; Savetamal, Alisa; Crombie, Roselle E; Cholewczynski, Walter; Atweh, Nabil; Possenti, Paul; Schulz, John T

    2013-01-01

    Donor sites from split-thickness skin grafts (STSG) impose significant pain on patients in the early postoperative period. We report the use of continuous local anesthetic infusion as a method for the management of postoperative STSG donor site pain. Patients undergoing single or dual, adjacent STSG harvest from the thigh (eight patients) or back (one patient) were included in this study. Immediately after STSG harvest, subcutaneous catheters were placed for continuous infusion of local anesthetic. Daily donor site-specific pain severity scores were prospectively recorded in nine patients receiving local anesthetic infusion. Patient characteristics, technical aspects, and postoperative complications were identified in the study. The thigh was the anatomic location chosen for most donor sites. A single catheter was placed for donor sites limited to 4 inches in width or less. A dual catheter system was used for those wider than 4 inches. An elastomeric pump delivered continuously a total of 4 ml/hr of a solution of 0.5% bupivacaine. The average anesthetic infusion duration was 3.1 days. A substantial decrease in worst, least, and average donor site pain scores was found from the first 24 hours to the second postoperative day in our patients, a treatment trend that continued through postoperative day 3. One patient developed minor anesthetic leakage from the catheter insertion site; and in three cases, accidental dislodgement of the catheters occurred. There were no cases of donor site secondary infection. All donor sites were completely epithelialized at 1-month follow-up. Continuous local anesthetic infusion is technically feasible and may represent an option for postoperative donor site pain control after STSG harvesting. Relative cost-benefit of the technique remains to be determined. PMID:23271060

  10. Synthesis of Two Local Anesthetics from Toluene: An Organic Multistep Synthesis in a Project-Oriented Laboratory Course

    ERIC Educational Resources Information Center

    Demare, Patricia; Regla, Ignacio

    2012-01-01

    This article describes one of the projects in the advanced undergraduate organic chemistry laboratory course concerning the synthesis of two local anesthetic drugs, prilocaine and benzocaine, with a common three-step sequence starting from toluene. Students undertake, in a several-week independent project, the multistep synthesis of a…

  11. Mass-spectrometric monitoring of the intravenous anesthetic concentration in the breathing circuit of an anesthesia machine

    NASA Astrophysics Data System (ADS)

    Elizarov, A. Yu.; Levshankov, A. I.

    2011-04-01

    Interaction between inhalational anesthetic sevoflurane and an absorber of CO2 (soda lime) in the breathing circuit of an anesthesia machine during low-flow anesthesia (0.5 l of a fresh gaseous mixture per minute) is studied with the mass-spectrometric method. Monitoring data for the concentration of sevoflurane and three toxic products of sevoflurane decompositions (substances A, B, and C) during anesthesia in the inspiration-expiration regime are presented. The highest concentration of substance A is found to be 65 ppm. The biochemical blood analysis before and after anesthesia shows that nephropathy is related to the function of liver toxicity. It is found that inhalational anesthetic sevoflurane influences the concentration of intravenous hypnotic propofol in blood.

  12. Low-dose combined spinal-epidural anesthesia for cesarean delivery: a comparison of three plain local anesthetics.

    PubMed

    Coppejans, H C; Vercauteren, M P

    2006-01-01

    The new local anesthetics have been poorly studied for intrathecal use during Cesarean section surely in low doses and in combination with an opioid substance. The purpose of the present study was to compare bupivacaine and the newer local anesthetics in equipotent doses. During the induction of combined spinal-epidural anesthesia, 91 elective Cesarean section patients were randomly assigned to receive a spinal injection of either 10 mg ropivacaine or 6.6 mg bupivacaine or levobupivacaine both combined with sufentanil 3.3 microg. After securing the epidural catheter patients were turned to the supine position respecting a 15 degrees left lateral tilt. The three local anesthetics were compared with respect to sensory and motor block, the need for epidural supplementation, the severity of hypotension and neonatal outcome. More patients in bupivacaine had a Bromage-3 motor block at incision. The ropivacaine group required additional local anesthetics by the epidural route in 23% of the cases versus 10% in the bupivacaine group and 9% with levobupivacaine. This caused the interval between the spinal injection and the end of surgery to be longer in the ropivacaine group. Hemodynamic values were comparable between the three groups although a trend towards better systolic blood pressures and a lower incidence of severe hypotension were noticed in favor of levobupivacaine. Apgar scores and umbilical pH values did not differ. When performing a low-dose combined spinal-epidural technique for Cesarean section, the present study confirms that the new local anesthetics can be used successfully, induce less motor block but that ropivacaine requires at least a 50% larger dose than bupivacaine or levobupivacaine. PMID:16617756

  13. Comparison of topical lidocaine/prilocaine anesthetic cream and local infiltration of 2% lidocaine for episioplasty in mares.

    PubMed

    Erkert, R S; Macallister, C G; Campbell, G; Payton, M E; Shawley, R; Clarke, C R

    2005-06-01

    Local anesthesia and tissue inflammation associated with lidocaine infiltration and lidocaine/prilocaine topical anesthetic cream for episioplasty in mares were compared. Twenty-two mares were randomly assigned to lidocaine or lidocaine/prilocaine topical anesthetic cream treatment groups. Perineum and vulva were cleaned, 8-12 g (approximately 1 g/cm per side of vulva) of topical anesthetic cream was applied, and the area was covered by plastic wrap 30 min prior to beginning procedure. Alternately, lidocaine was injected (1 mL) every centimeter just prior to the procedure. Episioplasty was conducted using standard methods, but employing simple interrupted sutures. Horses were not sedated and use of a twitch was recorded. Four millimeter punch biopsies were harvested 1, 3, and 10 days following episioplasty and scored for degree of inflammation by a blinded pathologist. Clinical inflammation scores were assigned when biopsies were obtained. Seven of 11 horses receiving lidocaine infiltration required twitching, but none of the horses that received the anesthetic cream required twitching. Six of 11 and seven of 11 of the lidocaine and anesthetic cream groups, respectively, required twitching for episioplasty. Except for the clinical scores on day 3, no statistical differences for clinical and histopathologic scores between samples from the two treatment groups for a given day were identified. Use of lidocaine/prilocaine topical anesthetic cream was as effective as lidocaine infiltration in providing local anesthesia when performing episioplasty in mares. Its use decreased the need for twitching horses as well as the risk of deformation of the labia caused by lidocaine infiltration. PMID:15953204

  14. Effects of regional limb perfusion volume on concentrations of amikacin sulfate in synovial and interstitial fluid samples from anesthetized horses.

    PubMed

    Godfrey, Jennifer L; Hardy, Joanne; Cohen, Noah D

    2016-06-01

    OBJECTIVE To evaluate the effect of volume of IV regional limb perfusion (IVRLP) on amikacin concentrations in synovial and interstitial fluid of horses. ANIMALS 8 healthy adult horses. PROCEDURES Each forelimb was randomly assigned to receive IVRLP with 4 mL of amikacin sulfate solution (250 mg/mL) plus 56 mL (total volume, 60 mL) or 6 mL (total volume, 10 mL) of lactated Ringer solution. Horses were anesthetized, and baseline synovial and interstitial fluid samples were collected. A tourniquet was placed, and the assigned treatment was administered via the lateral palmar digital vein. Venous blood pressure in the distal portion of the limb was recorded. Additional synovial fluid samples were collected 30 minutes (just before tourniquet removal) and 24 hours after IVRLP began; additional interstitial fluid samples were collected 6 and 24 hours after IVRLP began. RESULTS 30 minutes after IVRLP began, mean amikacin concentration in synovial fluid was significantly greater for the large-volume (459 μg/mL) versus small-volume (70 μg/mL) treatment. Six hours after IVRLP, mean concentration in interstitial fluid was greater for the large-volume (723 μg/mL) versus small-volume (21 μg/mL) treatment. Peak venous blood pressure after large-volume IVRLP was significantly higher than after small-volume IVRLP, with no difference between treatments in time required for pressure to return to baseline. CONCLUSIONS AND CLINICAL RELEVANCE Study findings suggested that large-volume IVRLP would deliver more amikacin to metacarpophalangeal joints of horses than would small-volume IVRLP, without a clinically relevant effect on local venous blood pressure, potentially increasing treatment efficacy. PMID:27227495

  15. Molecular determinants of prokaryotic voltage-gated sodium channels for recognition of local anesthetics.

    PubMed

    Shimomura, Takushi; Irie, Katsumasa; Fujiyoshi, Yoshinori

    2016-08-01

    Local anesthetics (LAs) inhibit mammalian voltage-gated Na(+) channels (Navs) and are thus clinically important. LAs also inhibit prokaryotic Navs (BacNavs), which have a simpler structure than mammalian Navs. To elucidate the detailed mechanisms of LA inhibition to BacNavs, we used NavBh, a BacNav from Bacillus halodurans, to analyze the interactions of several LAs and quaternary ammoniums (QAs). Based on the chemical similarity of QA with the tertiary-alkylamine (TAA) group of LAs, QAs were used to determine the residues required for the recognition of TAA by NavBh. We confirmed that two residues, Thr220 and Phe227, are important for LA binding; a methyl group of Thr220 is important for recognizing both QAs and LAs, whereas Phe227 is involved in holding blockers at the binding site. In addition, we found that NavBh holds blockers in a closed state, consistent with the large inner cavity observed in the crystal structures of BacNavs. These findings reveal the inhibition mechanism of LAs in NavBh, where the methyl group of Thr220 provides the main receptor site for the TAA group and the bulky phenyl group of Phe227 holds the blockers inside the large inner cavity. These two residues correspond to the two LA recognition residues in mammalian Navs, which suggests the relevance of the LA recognition between BacNavs and mammalian Navs. PMID:27273848

  16. Investigation of local anesthetic and antimycobacterial activity of Ottonia martiana Miq. (Piperaceae).

    PubMed

    Cunico, Miriam M; Trebien, Herbert A; Galetti, Fábio C; Miguel, Obdulio G; Miguel, Marilis D; Auer, Celso G; Silva, Célio L; de Souza, Ana Olívia

    2015-01-01

    Ottonia martiana is a plant popularly known in Brazil by the use for toothache. Ethanolic extract (EE), hexane fraction (HF), dichloromethane fraction (DF) and piperovatine obtained from O. martiana were assayed in vitro and in vivo. The acute toxicity of EE was determined, and LD50 values of 164.5 and 65.0 mg/kg by the oral and intraperitoneal routes, respectively, indicated a high toxicity for EE in vivo, explaining its popular use by topical administration only. A local anesthetic-like effect of EE and its fractions was observed in experimental models using pain induction, and such effect involved an analgesic action. The antimycobacterial activity of EE, HF, DF and piperovatine was evaluated against Mycobacterium tuberculosis H37Rv ATCC 27924. EE, HF, DF, and piperovatine showed a potential antimycobacterial effect with MICs of 16.0, 62.0, 62.0 and 8.0 μg/mL, respectively. Piperovatine was more effective than the EE or the other fractions. The selectivity index (SI=IC50/MIC) values calculated for EE, HF, DF and piperovatine based on the MICs and the cytotoxicity against J774 macrophages (IC50 by MTT assay) revealed values of 6.43, 2.34, 1.5 and 9.66, respectively. PMID:26628019

  17. Drug binding to the acetylcholine receptor: Nitroxide analogs of phencyclidine and a local anesthetic

    SciTech Connect

    Palma, A.L.

    1988-01-01

    The interaction of noncompetitive inhibitors (NCIs) with Torpedo californica native nicotinic acetylcholine receptor (nAChR) membranes was examined primarily by the technique of electron paramagnetic resonance (EPR) spectroscopy. The goal of this work being to define some of the physical characteristics for the site(s) of association between an NCI and the nAChR membrane. A nitroxide labeled analog of a quaternary amine local anesthetic, 2-(N,N-dimethyl-N-4-(2,2,6,6-tetramethylpiperidinoxyl)amino)-ethyl 4-hexyloxybenzoate iodide (C6SLMeI), displays a strongly immobilized EPR component when added to nAChR membranes in the presence of carbamylcholine (carb). To further this work, a nitroxide labeled analog of phencyclidine (PCP), a potent NCI, was synthesized. 4-phenyl-4-(1-piperidinyl)-2,2,6,6-tetramethylpiperidinoxyl (PPT) exhibited one-third the potency of PCP in inhibiting nAChR mediated ion flux, and from competition binding studies with ({sup 3}H)PCP displayed a K{sub D} of 0.21 {mu}M towards a carb desensitized nAChR and a K{sub 0.5} of 18 {mu}M for a resting {alpha}-bungarotoxin treated nAChR.

  18. Local anesthetic and antiepileptic drug access and binding to a bacterial voltage-gated sodium channel.

    PubMed

    Boiteux, Céline; Vorobyov, Igor; French, Robert J; French, Christopher; Yarov-Yarovoy, Vladimir; Allen, Toby W

    2014-09-01

    Voltage-gated sodium (Nav) channels are important targets in the treatment of a range of pathologies. Bacterial channels, for which crystal structures have been solved, exhibit modulation by local anesthetic and anti-epileptic agents, allowing molecular-level investigations into sodium channel-drug interactions. These structures reveal no basis for the "hinged lid"-based fast inactivation, seen in eukaryotic Nav channels. Thus, they enable examination of potential mechanisms of use- or state-dependent drug action based on activation gating, or slower pore-based inactivation processes. Multimicrosecond simulations of NavAb reveal high-affinity binding of benzocaine to F203 that is a surrogate for FS6, conserved in helix S6 of Domain IV of mammalian sodium channels, as well as low-affinity sites suggested to stabilize different states of the channel. Phenytoin exhibits a different binding distribution owing to preferential interactions at the membrane and water-protein interfaces. Two drug-access pathways into the pore are observed: via lateral fenestrations connecting to the membrane lipid phase, as well as via an aqueous pathway through the intracellular activation gate, despite being closed. These observations provide insight into drug modulation that will guide further developments of Nav inhibitors. PMID:25136136

  19. Effect of Washes and Centrifugation on the Efficacy of Lipofilling With or Without Local Anesthetic

    PubMed Central

    Mirbeau, Sophie; Gence, Lydie; Hivernaud, Vincent; Delarue, Pierre; Hulard, Olivier; Festy, Franck; Roche, Regis

    2015-01-01

    Background: Among the different parameters that influence fat graft survival and lipofilling success, the use of local anesthetic and the way to process the fat before injection have often been pointed out. Likewise, we evaluated different techniques for processing adipose tissue before its injection and analyzed the quality of the grafts. Methods: Adipose tissue from the same patient was gently harvested from one side of the abdomen after infiltration of a tumescent solution without lidocaine and from the other side of the abdomen using a tumescent solution containing lidocaine 2%. Harvested tissue was prepared with different protocols, from simple decantation to advanced protocols including single or multiple washes and centrifugations. Each type of processed adipose tissue was then injected subcutaneously into immunodeficient mice. Adipose grafts were collected after 1 month and analyzed by histology with a detailed scoring method. Results: After lidocaine use, decantation protocol led to adipose grafts of poor quality with high resorption rate and oil vacuole formation. Larger grafts were obtained after centrifugation, but centrifugation alone resulted in increased fibrosis and necrosis, with or without the use of lidocaine. Finally, multiple washes and centrifugations greatly improved the quality of the lipografts. Conclusions: Centrifugation alone is not sufficient and must be associated with multiple washes to improve graft quality. This article aims to provide further evidence of lidocaine and washing/centrifugation effects in fat grafting to provide easy tips aimed at ensuring graft efficiency with a long-term clinical outcome. PMID:26495209

  20. The challenge of evaluating pain and a pre-incisional local anesthetic block

    PubMed Central

    Pascoe, Peter J.; Lascelles, B. Duncan X.; Kass, Philip H.

    2014-01-01

    Background. Our objective was to test the effectiveness of a local anesthetic line block administered before surgery in reducing postoperative pain scores in dogs undergoing ovariohysterectomy (OVHX). Methods. This study is a prospective, randomized, blinded, clinical trial involving 59 healthy female dogs. An algometric pressure-measuring device was used to determine nociceptive threshold, and compared to three subjective pain scales. Group L/B received a line block of lidocaine (4 mg/kg) and bupivacaine (1 mg/kg) subcutaneously in the area of the incision site and saline subcutaneously as premedication; group L/BM (positive control) received a similar block and morphine (0.5 mg/kg) subcutaneously for premedication; and group SS (negative control) received a saline line block and saline premedication. Criteria for rescue analgesia were defined before the study. Dogs were assessed prior to surgery, at extubation (time 0) and at 2, 4, 6, 8 and 24 h post-recovery. The data were analyzed with one-way ANOVA, and a Split Plot Repeated Measures ANOVA with one grouping factor and one repeat factor (time). P < 0.05 was considered statistically significant. Results. Approximately 33% of dogs required rescue analgesia at some point during the study, with no significant difference between groups. There was no significant difference between treatment groups with any assessment method. Conclusions. As there were no statistically significant differences between positive and negative controls, the outcome of this technique cannot be proven. PMID:24765575

  1. Antioxidant's cytoprotective effects on rotator cuff tenofibroblasts exposed to aminoamide local anesthetics.

    PubMed

    Kim, Ra Jeong; Hah, Young-Sool; Kang, Jae-Ran; Park, Hyung Bin

    2015-07-01

    Local anesthetics (LA) are among the drugs most frequently used for musculoskeletal problems, in procedures ranging from diagnosis to postoperative pain control. The cytotoxicity of LA is an emerging area of concern. The purpose of this study was to determine whether cyanidin, an antioxidant, exerts cytoprotective effects against tenofibroblast death induced by LA. Primary cultured human rotator cuff tenofibroblasts were used to evaluate the cytotoxicity of these LA: Ropivacaine (0.075%), Bupivacaine (0.05%), and Lidocaine (0.2%). The effects of cyanidin (100 μg/ml) on the cytotoxicity induced by these LA were investigated. Cell viability, ROS production, caspase-3/7 activity, and expressions of phospho-extracellular signal-regulated kinases (ERK), phospho-p38, phospho-c-Jun N-terminal kinase (JNK), and cleaved PARP-1 were evaluated. Exposure to LA significantly induced cell death (p < 0.001), ROS production (p ≤ 0.04), the activation of caspase-3/7 (p < 0.001), and the increased expressions of phospho-ERK, phospho-p38, phospho-JNK, and cleaved PARP-1. These LA-induced cytotoxic effects were reduced by cyanidin. These data indicate that cyanidin, an antioxidant, has cytoprotective effects against LA-induced cytotoxicity to rotator cuff tenofibroblasts. PMID:25639557

  2. [The effect of charged local anesthetics on the inactivation of Ca2+-activated Cl-channels of characean algae].

    PubMed

    Kataev, A A; Zherelova, O M; Berestovskiĭ, G N

    1988-01-01

    Effects of local anesthetics (LA) and a number of organic cations on Ca2+-activated Cl-channels in plasmalemma of intracellularly perfused giant algae Nitellopsis obtusa were studied using voltage-clamp technique. It was shown earlier that Ca2+ ions cause irreversible inactivation of Cl-channels with a characteristic time equal to a few minutes, but not only activate Cl-channels. It has been found that amphiphilic cations (AC), including LA+, introduced intracellularly together with Ca2+ produced delayed action on the beginning of the inactivation process (approximately ten minutes) producing no effect on activation during this period. The time of delayed action was linearly dependent on the concentrations ratio alpha = [AC]/[Ca2+]. Procaine is the most effective agent in this respect, the time of its delayed action on the inactivation process being 20 min at alpha = 1. LA in the neural form, hydrophilic AC of tetraethylammonium, as well as LA+ from the outside had no effect on Cl-channels. Cl-channels inactivated "irreversibly" by Ca2+ ions may be restored after addition of AC in Ca2+-containing perfusion medium. PMID:2470412

  3. Decreased narcotic use with an implantable local anesthetic catheter after deep inferior epigastric perforator flap breast reconstruction.

    PubMed

    Boehmler, James H; Venturi, Mark L; Nahabedian, Maurice Y

    2009-06-01

    This study evaluated narcotic use after deep inferior epigastric perforator flap breast reconstruction when a local anesthetic catheter was used. A retrospective analysis was performed comparing 40 consecutive control patients (no catheter) to 40 consecutive study patients who had received a pain pump catheter. The catheter was left in the abdomen for 72 hours. Using an equianalgesic table, all narcotic doses (oral and intravenous) were converted to intravenous morphine equivalents. Initial average 24-hour morphine requirement for the control group was 42 mg compared with 33 mg for the study group (P = 0.04). Total hospitalization average morphine requirement for the control group was 71 mg compared with 55 mg for the catheter group (P = 0.03). The use of an implantable local anesthetic catheter placed in the abdomen can decrease narcotic use in the postoperative period after deep inferior epigastric perforator flap breast reconstruction. PMID:19461271

  4. Analysis of Efficacy Differences between Caudal and Lumbar Interlaminar Epidural Injections in Chronic Lumbar Axial Discogenic Pain: Local Anesthetic Alone vs. Local Combined with Steroids

    PubMed Central

    Manchikanti, Laxmaiah; Pampati, Vidyasagar; Benyamin, Ramsin M.; Boswell, Mark V.

    2015-01-01

    Study Design: Comparative assessment of randomized controlled trials of caudal and lumbar interlaminar epidural injections in chronic lumbar discogenic pain. Objective: To assess the comparative efficacy of caudal and lumbar interlaminar approaches of epidural injections in managing axial or discogenic low back pain. Summary of Background Data: Epidural injections are commonly performed utilizing either a caudal or lumbar interlaminar approach to treat chronic lumbar axial or discogenic pain, which is pain exclusive of that associated with a herniated intervertebral disc, or that is due to degeneration of the zygapophyseal joints, or due to dysfunction of the sacroiliac joints, respectively. The literature on the efficacy of epidural injections in managing chronic axial lumbar pain of presumed discogenic origin is limited. Methods: The present analysis is based on 2 randomized controlled trials of chronic axial low back pain not caused by disc herniation, radiculitis, or facet joint pain, utilizing either a caudal or lumbar interlaminar approach, with a total of 240 patients studied, and a 24-month follow-up. Patients were assigned to receive either local anesthetic only or local anesthetic with a steroid in each 60 patient group. Results: The primary outcome measure was significant improvement, defined as pain relief and functional status improvement of at least 50% from baseline, which was reported at 24-month follow-ups in 72% who received local anesthetic only with a lumbar interlaminar approach and 54% who received local anesthetic only with a caudal approach. In patients receiving local anesthetic with a steroid, the response rate was 67% for those who had a lumbar interlaminar approach and 68% for those who had a caudal approach at 12 months. The response was significantly better in the lumbar interlaminar group who received local anesthetic only, 77% versus 56% at 12 months and 72% versus 54% at 24 months. Conclusion: This assessment shows that in patients

  5. Pain Control after Total Knee Arthroplasty: Comparing Intra-Articular Local Anesthetic Injection with Femoral Nerve Block

    PubMed Central

    Kao, Shengchin; Lee, Hungchen; Cheng, Chihwen; Lin, Chingfeng; Tsai, Hsini

    2015-01-01

    Background. Direct intra-articular injection of low doses of local anesthetic (IALA) after closure of the joint capsule remains controversial for pain control after total knee arthroplasty (TKA). Methods. A retrospective study comparing patients receiving IALA with high doses (0.5% bupivacaine 60 mL) of local anesthetics or FNB in addition to intravenous patient-controlled analgesia with opioids for pain management after TKA was conducted. The primary end point was to compare the analgesic efficacy and early ambulation between the two groups. Results. No significant differences between the two groups in pain intensity, cumulative opioid consumption, incidences of opioid-related side effects, the time interval from the end of operation to the first time the patient could walk assisted with a walker postoperatively, and postoperative hospital stay were identified. Three patients in the IALA group but none in the FNB group walked within 12 hours after the end of operation. Summary. IALA with high doses of local anesthetics provides comparable analgesic efficacy as single-shot FNB after TKA and might be associated with earlier ambulation than FNB postoperatively. PMID:26064937

  6. Survey of responsible handling of local anesthetic in Indian dental operatory

    PubMed Central

    Rooban, Thavarajah; Rao, Umadevi Krishnamohan; Joshua, Elizabeth; Ranganathan, Kannan

    2013-01-01

    Background: Dental operatory requires handling of numerous toxic fluids such as denture acrylic monomer, alcohol and formalin for effective oral care delivery. The efficacy and responsible handling of such fluids has not been analyzed among Indian dentists and this study aims to address this lacunae. Materials and Methods: Closed ended questionnaire was distributed through email to Indian dentists in July 2012. After inclusion/exclusion criteria, 1484 practitioners constituted the study group with a response rate of 52%. Statistics: SPSS® Version 17.0 (SPSS-IBM Inc., IL, USA) was used to carry out statistical analysis. Descriptive statistics were presented. Chi square test was used to identify the association between the parameters; P ≤ 0.05 was considered as statistically significant. Results: Males (80.8%), undergraduates (78%), exclusive practitioners (81.2%), urban practitioners (68.5%) were the predominant respondents. Predominant of the respondents (97%) used local anesthetic (LA) from bottles. Eight percent have encountered instances of injecting formalin instead of LA in their settings. Safe disposal rules and regulations (P ≤ 0.05), opinion on injecting the other fluids instead of LA as a severe negligent act (P ≤ 0.05) were statistically significant between age groups. Educational status did not appear to influence the outcome. Only a third of the respondents were aware of the rules and regulations for safe disposal of empty LA bottles while 49.1% were not aware of them and willing to learn. Discussion: The lacunae in responsible handling of toxic fluids need to be addressed to prevent inadvertent and negligence suits against dentists, highlighting the need through continuing dental education programmes. PMID:24255564

  7. Nuclear Quadrupole Resonance Study of the Nitrogen Mustards and Local Anesthetics.

    NASA Astrophysics Data System (ADS)

    Buess, Michael Lee

    The density matrix description of pulsed nitrogen -14 nuclear quadrupole resonance (NQR) spin-echoes is presented. The parallel between this problem, when formulated in terms of the fictitious spin- 1/2 operators, and that of spin - 1/2 NMR spin-echoes in liquids is discussed along with the complications which arise in multiple-pulse NQR experiments in powders due to the random orientation of the electric field gradient tensors. The equipment and procedures involved in searching for, detecting and identifying NQR resonances using pulsed techniques are described. The ('14)N NQR spectra of several nitrogen mustard compounds in the solid state are reported and analyzed in the framework of the Townes and Dailey theory. For the aniline derivatives, a correlation exists between l -(sigma), l being the nitrogen lone-pair electron density and (sigma) the average N-C sigma bond electron density, and the enhanced Hammett sigma constant (sigma)('-). An improved correlation is obtained between l-(sigma) and (sigma)(,R)('-), which emphasizes the importance of resonance effects in determining l-(sigma). The increase of hydrolysis and alkylation rates with increasing values of l-(sigma) is in agreement with the identification of the cyclic immonium ion as the intermediate in the hydrolysis and alkylation processes of the aromatic nitrogen mustards. A possible correlation is noted between the ('35)Cl NQR spectra for some of the mustards and measures of toxic and antitumor activity. ('14)N NQR spectra for several local anesthetics in the solid state are also reported and analyzed using the Townes and Dailey approach. The changes in the electron distributions at various nitrogen sites, produced by protonating the tertiary amino nitrogen, are discussed and shown to be in general agreement with expectations bases on the increased electrophilic character of the protonated amino group.

  8. Skin testing and incremental challenge in the evaluation of adverse reactions to local anesthetics.

    PubMed

    Schatz, M

    1984-10-01

    True allergic reactions to local anesthetics (LAs) probably make up no more than 1% of all adverse LA reactions. A diagnosis of true potential allergic reactivity is made difficult because (1) the history of the prior reaction may be vague or equivocal and (2) the lack of identification of the actual specific LA hapten-carrier complex limits the potential usefulness of immunologic tests. Nonetheless, since avoidance of LAs may be associated with substantial increased pain or increased risk and because true allergic reactions are rare, investigators and clinicians have used skin testing, incremental challenge, or both as a means of identifying a safe LA for a patient with a history of a prior adverse reaction. Review of the literature dealing with LA skin testing and incremental challenge suggests the following: (1) Skin testing with LAs may correlate with a history of an adverse reaction but may produce systemic adverse reactions, especially with undiluted drug. (2) Although false positive skin tests have been reported, most skin-tested patients who subsequently tolerate an LA have a negative skin test to that drug, and false negative skin tests have not been clearly documented. (3) Incremental challenge beginning with diluted LA is a safe and effective means of identifying a drug that a patient with a history of a prior adverse reaction can tolerate. (4) Current concepts of non-cross-reacting LA groups may be useful in the choice of a drug for use in skin testing and incremental challenge. (5) Preservatives in LAs may account for some but probably not the majority of adverse reactions to LAs. On the basis of this literature review, a practical protocol including dilutional skin testing and incremental challenge is presented for use in evaluating patients with prior adverse reactions to LAs. PMID:6491108

  9. Cytotoxicity of solid lipid nanoparticles and nanostructured lipid carriers containing the local anesthetic dibucaine designed for topical application

    NASA Astrophysics Data System (ADS)

    Barbosa, R. M.; da Silva, C. M. G.; Bella, T. S.; de Araújo, D. R.; Marcato, P. D.; Durán, N.; de Paula, E.

    2013-04-01

    Dibucaine (DBC) is powerful long-lasting local anesthetic, but it is also considered fairly toxic to the CNS. Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) have attracted attention as carriers for drug delivery. The aim of this study was to develop and to evaluate the cytotoxic activity of DBC-loaded SLN and NLC against 3T3 fibroblast and HaCat keratinocyte cells. The SLN and NLC had myristyl myristate and Liponate®GC as their lipid matrices, respectively, plus a surfactant. SLN and NLC were characterized in terms in their diameter, size distribution, surface charge and DBC encapsulation efficiency. The particle size of SLN and NLC were around 234.33 and 166.62 nm, respectively. The polydispersity index was kept below 0.2 for both nanomaterials. Negative surface charges were observed for both nanoparticles, which decreased in the presence of the anesthetic. Encapsulation efficiency reached 76% and 90%, respectively, in SLN and NLC. DBC alone was found to be toxic to 3T3 and HaCat cells in culture. However, NLC and SLN loaded DBC decreased its intrinsic cytotoxic effect against 3T3 and HaCat cells. In conclusion, encapsulation of DBC in SLN and NLC decreased the in vitro toxicity of the local anesthetic, indicating the potential of these nanocarriers for clinical applications.

  10. Prospective randomized comparison between ultrasound-guided saphenous nerve block within and distal to the adductor canal with low volume of local anesthetic

    PubMed Central

    Adoni, Areti; Paraskeuopoulos, Tilemachos; Saranteas, Theodosios; Sidiropoulou, Tatiana; Mastrokalos, Dimitrios; Kostopanagiotou, Georgia

    2014-01-01

    Background and Aims: The anatomic site and the volume of local anesthetic needed for an ultrasound-guided saphenous nerve block differ in the literature. The purpose of this study was to examine the effect of two different ultrasound-guided low volume injections of local anesthetic on saphenous and vastus medialis nerves. Materials and Methods: Recruited patients (N = 48) scheduled for orthopedic surgery were randomized in two groups; Group distal adductor canal (DAC): Ultrasound-guided injection (5 ml of local anesthetic) distal to the inferior foramina of the adductor canal. Group adductor canal (AC): Ultrasound-guided injection (5 ml local anesthetic) within the adductor canal. Following the injection of local anesthetic, block progression was monitored in 5 min intervals for 15 min in the sartorial branches of the saphenous nerve and vastus medialis nerve. Results: Twenty two patients in each group completed the study. Complete block of the saphenous nerve was observed in 55% and 59% in Group AC and DAC, respectively (P = 0.88). The proportion of patients with vastus medialis weakness at 15 min in Group AC, 36%, was significantly higher than in Group DAC (0/22), (P = 0.021). Conclusions: Low volume of local anesthetic injected within the adductor canal or distally its inferior foramina leads to moderate success rate of the saphenous nerve block, while only the injection within the adductor canal may result in vastus medialis nerve motor block. PMID:25190947

  11. Development of a minimum-anesthetic-concentration depression model to study the effects of various analgesics in goldfish (Carassius auratus).

    PubMed

    Ward, Jessica L; McCartney, Sean P; Chinnadurai, Sathya K; Posner, Lysa P

    2012-06-01

    Teleost fish demonstrate the neurophysiologic capacity to experience pain and analgesia. A common model for assessing analgesic effect is the reduction of minimum anesthetic concentration (MAC). The present study adapted the model of MAC depression to evaluate the analgesic effects of morphine, butorphanol, medetomidine, and ketoprofen in goldfish (Carassius auratus). MAC was determined by an up-down method of sequential population sampling, anesthetizing fish with tricaine methanesulfonate (MS-222) in concentration increments of 10 parts per million (ppm), and using intramuscular needle insertion as a supramaximal noxious stimulus. Baseline MAC was determined in triplicate at the beginning (MACi) and conclusion (MACe) of the experiment (approximately 60 days). For drug trials, MAC was redetermined 1 hr after administration of morphine (10, 20, 40 mg/kg i.m.), butorphanol (0.1, 0.2, 0.4 mg/kg i.m.), medetomidine (0.01, 0.015, 0.025 mg/kg i.m.), ketoprofen (0.5, 1.0, 2.0 mg/kg i.m.), or saline control. Each drug/dose was tested in random order with a > 6-day washout period. MACi and MACf were 163 and 182 ppm, respectively, and were significantly different from each other (P = 0.02). All doses of morphine and ketoprofen decreased MAC below MACi. The highest dose of medetomidine decreased MAC below MACi. The lowest dose of butorphanol decreased MAC below MACi, but higher doses increased MAC above MACf. The authors conclude that MAC determination in fish using MS-222 was feasible and reproducible in the short term. The fact that MAC increased over time and/or exposure may limit the usefulness of MS-222 in MAC depression studies. Morphine and ketoprofen decrease anesthetic needs in goldfish and may provide analgesia. PMID:22779222

  12. Evaluation of cerebrospinal fluid lactate and plasma lactate concentrations in anesthetized dogs with and without intracranial disease

    PubMed Central

    Caines, Deanne; Sinclair, Melissa; Wood, Darren; Valverde, Alexander; Dyson, Doris; Gaitero, Luis; Nykamp, Stephanie

    2013-01-01

    The objectives of this study were to establish a reference interval for canine cerebrospinal fluid lactate (CSFL) and to compare CSFL and plasma lactate (PL) concentrations in anesthetized dogs with and without intracranial disease. Using a prospective study, canine blood and cerebrospinal fluid were collected for lactate analysis in 11 dogs with intracranial disease after undergoing magnetic resonance imaging (MRI) (Group ID-MRI), in 10 healthy dogs post-MRI (Group H-MRI), and in 39 healthy dogs after induction of anesthesia (Group H-Sx). Dogs were anesthetized for the procedures using different anesthetic protocols. Neurological scores (NS) and sedation scores (SS) were assessed pre-anesthesia in ID-MRI dogs. The CSFL reference interval [90% confidence interval (CI) for lower and upper limits] was 1.1 (1.0 to 1.2) to 2.0 (2.0 to 2.1) mmol/L. Mean ± SD CSFL concentrations were: ID-MRI, 2.1 ± 0.8; H-MRI, 1.6 ± 0.4; and H-Sx, 1.6 ± 0.2 mmol/L. There was a tendency for higher CSFL in dogs in the ID-MRI group than in those in the H-MRI or H-Sx groups (P = 0.12). There was agreement between CSFL and PL in ID-MRI dogs (P = 0.007), but not in dogs in H-MRI (P = 0.5) or H-Sx (P = 0.2). Of the ID-MRI dogs, those with worse NS had higher CSFL (r2 = 0.44). The correlation between CSFL and PL in dogs with intracranial disease and between worse NS and higher CSFL warrants further investigation into the use of CSFL and PL for diagnostic and prognostic purposes. PMID:24124273

  13. Effects of Single Injection of Local Anesthetic Agents on Intervertebral Disc Degeneration: Ex Vivo and Long-Term In Vivo Experimental Study

    PubMed Central

    Iwasaki, Koji; Sudo, Hideki; Yamada, Katsuhisa; Higashi, Hideaki; Ohnishi, Takashi; Tsujimoto, Takeru; Iwasaki, Norimasa

    2014-01-01

    Background Analgesic discography (discoblock) can be used to diagnose or treat discogenic low back pain by injecting a small amount of local anesthetics. However, recent in vitro studies have revealed cytotoxic effects of local anesthetics on intervertebral disc (IVD) cells. Here we aimed to investigate the deteriorative effects of lidocaine and bupivacaine on rabbit IVDs using an organotypic culture model and an in vivo long-term follow-up model. Methods For the organotypic culture model, rabbit IVDs were harvested and cultured for 3 or 7 days after intradiscal injection of local anesthetics (1% lidocaine or 0.5% bupivacaine). Nucleus pulposus (NP) cell death was measured using confocal microscopy. Histological and TUNEL assays were performed. For in vivo study, each local anesthetic was injected into rabbit lumbar IVDs under a fluoroscope. Six or 12 months after the injection, each IVD was prepared for magnetic resonance imaging (MRI) and histological analysis. Results In the organotypic culture model, both anesthetic agents induced time-dependent NP cell death; when compared with injected saline solution, significant effects were detected within 7 days. Compared with the saline group, TUNEL-positive NP cells were significantly increased in the bupivacaine group. In the in vivo study, MRI analysis did not show any significant difference. Histological analysis revealed that IVD degeneration occurred to a significantly level in the saline- and local anesthetics-injected groups compared with the untreated control or puncture-only groups. However, there was no significant difference between the saline and anesthetic agents groups. Conclusions/Significance In the in vivo model using healthy IVDs, there was no strong evidence to suggest that discoblock with local anesthetics has the potential of inducing IVD degeneration other than the initial mechanical damage of the pressurized injection. Further studies should be performed to investigate the deteriorative effects of

  14. Tetracaine, a local anesthetic, preferentially induces translational inhibition with processing body formation rather than phosphorylation of eIF2α in yeast.

    PubMed

    Araki, Tomoyuki; Toh-e, Akio; Kikuchi, Yoshiko; Watanabe, Chihiro K; Hachiya, Takushi; Noguchi, Ko; Terashima, Ichiro; Uesono, Yukifumi

    2015-02-01

    It is unclear whether local anesthetics, such as tetracaine, and antipsychotics, such as phenothiazines, act on lipids or proteins. In Saccharomyces cerevisiae, these drugs inhibit growth, translation initiation, and actin polarization, and induce cell lysis at high concentrations. These activities are likely due to the cationic amphiphilic structure common to these agents. Although drug-induced translational inhibition is conserved in mammalian cells, other mechanisms, including the phosphorylation of eIF2α, a eukaryotic translational initiation factor, remain poorly understood. At a concentration of 10 mM, tetracaine rapidly inhibited translation initiation and lysed cells, whereas, at 2.5 mM, it slowly induced inhibition without lysis. The pat1 disruptant defective in mRNA decapping and the xrn1 disruptant defective in 5'-3' exoribonuclease were partially resistant to translational inhibition by tetracaine at each concentration, but the gcn2 disruptant defective in the eIF2α kinase was not. Phosphorylation of eIF2α was induced by 10 mM but not by 2.5 mM tetracaine, whereas processing bodies (P-bodies) were formed at 2.5 mM in Pat1-dependent and -independent manners. Therefore, administration of tetracaine inhibits translation initiation with P-body formation at both concentrations but acts via the Gcn2-eIF2α system only at the higher concentration. Because other local anesthetics and phenothiazines induced Pat1-dependent P-body formation, the mechanisms involved in translational inhibition by these cationic amphiphiles are similar. These results suggest that this dose-dependent biphasic translational inhibition by tetracaine results from an increase in membrane proteins that are indirectly inhibited by nonspecific interactions of cationic amphiphiles with membrane lipids. PMID:25119673

  15. Effects of magnesium sulfate and propofol on the minimum alveolar concentration preventing motor movement in sevoflurane-anesthetized dogs.

    PubMed

    Johnson, Alanna N; Seddighi, Reza; Rohrbach, Barton W; Cox, Sherry K; Egger, Christine M; Martin-Flores, Manuel; Doherty, Thomas J

    2016-06-01

    OBJECTIVE To evaluate the effect of MgSO4, alone and in combination with propofol, on the minimum alveolar concentration preventing motor movement (MACNM) in sevoflurane-anesthetized dogs. ANIMALS 6 healthy purpose-bred adult male Beagles (least squares mean ± SEM body weight, 12.0 ± 1.1 kg). PROCEDURES Dogs were anesthetized 3 times at weekly intervals. The MACNM was measured 45 minutes after induction of anesthesia (baseline; MACNM-B) and was determined each time by use of a noxious electrical stimulus. Treatments were administered as a loading dose and constant rate infusion (CRI) as follows: treatment 1, MgSO4 loading dose of 45 mg/kg and CRI of 15 mg/kg/h; treatment 2, propofol loading dose of 4 mg/kg and CRI of 9 mg/kg/h; and treatment 3, MgSO4 and propofol combination (same doses used previously for each drug). A mixed-model ANOVA and Tukey-Kramer tests were used to determine effects of each treatment on the percentage decrease from MACNM-B. Data were reported as least squares mean ± SEM values. RESULTS Decrease from MACNM-B was 3.4 ± 3.1%, 48.3 ± 3.1%, and 50.3 ± 3.1%, for treatments 1, 2, and 3, respectively. The decrease for treatments 2 and 3 was significantly different from that for treatment 1; however, no significant difference existed between results for treatments 2 and 3. CONCLUSIONS AND CLINICAL RELEVANCE MgSO4 did not affect MACNM, nor did it potentiate the effects of propofol on MACNM. Administration of MgSO4 in this study appeared to provide no clinical advantage as an anesthetic adjuvant. PMID:27227494

  16. Effect of topical local anesthetic application to skin harvest sites for pain management in burn patients undergoing skin-grafting procedures.

    PubMed Central

    Jellish, W S; Gamelli, R L; Furry, P A; McGill, V L; Fluder, E M

    1999-01-01

    OBJECTIVE: To determine if topical administration of local anesthesia, applied to fresh skin-harvest sites, reduces pain and analgesic requirements after surgery. SUMMARY BACKGROUND DATA: Nonopioid treatments for pain after therapeutic procedures on patients with burns have become popular because of the side effects associated with narcotics. The topical administration of local anesthesia originally offered little advantage because of poor epidermal penetration. METHODS: This study compares 2% lidocaine with 0.5% bupivacaine or saline, topically applied after skin harvest, to determine what effect this may have on pain and narcotic use. Sixty patients with partial- or full-thickness burns to approximately 10% to 15% of their body were randomly divided into three groups: group 1 received normal saline, group 2 had 0.5% bupivacaine, and group 3 had 2% lidocaine sprayed onto areas immediately after skin harvest. Blood samples were subsequently obtained to measure concentrations of the local anesthetic. Hemodynamic variables after surgery, wake-up times, emetic symptoms, pain, and narcotic use were compared. RESULTS: Higher heart rates were noted in the placebo group than in those receiving lidocaine or bupivacaine. No differences were noted in recovery from anesthesia or emetic symptoms. Pain scores were lower and 24-hour narcotic use was less in patients who received lidocaine. Plasma lidocaine levels were greater than bupivacaine at all time points measured. CONCLUSIONS: Topical lidocaine applied to skin-harvest sites produced an analgesic effect that reduced narcotic requirements compared with patients who received bupivacaine or placebo. Local anesthetic solutions aerosolized onto skin-harvest sites did not affect healing or produce toxic blood concentrations. PMID:9923808

  17. Efficacy of Benzocaine 20% Topical Anesthetic Compared to Placebo Prior to Administration of Local Anesthesia in the Oral Cavity: A Randomized Controlled Trial

    PubMed Central

    de Freiras, Guilherme Camponogara; Pozzobon, Roselaine Terezinha; Blaya, Diego Segatto; Moreira, Carlos Heitor

    2015-01-01

    The aim of the present study was to compare the effects of a topical anesthetic to a placebo on pain perception during administration of local anesthesia in 2 regions of the oral cavity. A split-mouth, double-blind, randomized clinical trial design was used. Thirty-eight subjects, ages 18–50 years, American Society of Anesthesiologists I and II, received 4 anesthetic injections each in regions corresponding to the posterior superior alveolar nerve (PSA) and greater palatine nerve (GPN), totaling 152 sites analyzed. The side of the mouth where the topical anesthetic (benzocaine 20%) or the placebo was to be applied was chosen by a flip of a coin. The needle used was 27G, and the anesthetic used for administration of local anesthesia was 2% lidocaine with 1:100,000 epinephrine. After receiving the administration of local anesthesia, each patient reported pain perception on a visual analog scale (VAS) of 100-mm length. The results showed that the topical anesthetic and the placebo had similar effects: there was no statistically significant VAS difference between the PSA and the GPN pain ratings. A higher value on the VAS for the anesthesia of the GPN, relative to the PSA, was observed for both groups. Regarding gender, male patients had higher values on the VAS compared with female patients, but these differences were not meaningful. The topical anesthetic and the placebo had similar effects on pain perception for injection of local anesthesia for the PSA and GPN. PMID:26061572

  18. Comparison of the efficacy of saline, local anesthetics, and steroids in epidural and facet joint injections for the management of spinal pain: A systematic review of randomized controlled trials

    PubMed Central

    Manchikanti, Laxmaiah; Nampiaparampil, Devi E.; Manchikanti, Kavita N.; Falco, Frank J.E.; Singh, Vijay; Benyamin, Ramsin M.; Kaye, Alan D.; Sehgal, Nalini; Soin, Amol; Simopoulos, Thomas T.; Bakshi, Sanjay; Gharibo, Christopher G.; Gilligan, Christopher J.; Hirsch, Joshua A.

    2015-01-01

    Background: The efficacy of epidural and facet joint injections has been assessed utilizing multiple solutions including saline, local anesthetic, steroids, and others. The responses to these various solutions have been variable and have not been systematically assessed with long-term follow-ups. Methods: Randomized trials utilizing a true active control design were included. The primary outcome measure was pain relief and the secondary outcome measure was functional improvement. The quality of each individual article was assessed by Cochrane review criteria, as well as the criteria developed by the American Society of Interventional Pain Physicians (ASIPP) for assessing interventional techniques. An evidence analysis was conducted based on the qualitative level of evidence (Level I to IV). Results: A total of 31 trials met the inclusion criteria. There was Level I evidence that local anesthetic with steroids was effective in managing chronic spinal pain based on multiple high-quality randomized controlled trials. The evidence also showed that local anesthetic with steroids and local anesthetic alone were equally effective except in disc herniation, where the superiority of local anesthetic with steroids was demonstrated over local anesthetic alone. Conclusion: This systematic review showed equal efficacy for local anesthetic with steroids and local anesthetic alone in multiple spinal conditions except for disc herniation where the superiority of local anesthetic with steroids was seen over local anesthetic alone. PMID:26005584

  19. Comparison of Dexmedetomidine and Clonidine as Adjuvants to Local Anesthetics for Intrathecal Anesthesia: A Meta-Analysis of Randomized Controlled Trials.

    PubMed

    Zhang, Changsheng; Li, Changtian; Pirrone, Massimiliano; Sun, Li; Mi, Weidong

    2016-07-01

    The authors performed a meta-analysis to compare the characteristics of clonidine and dexmedetomidine as adjuvants to local anesthetic in intravertebral anesthesia. Four investigators independently searched electronic databases for randomized trials comparing the characteristics of clonidine vs dexmedetomidine as adjuvants to local anesthetic on adults. The endpoints were onset of analgesia, sensory and motor block, and duration of analgesia. A random-effects model was used to perform quantitative analysis. Seven studies comprising 354 subjects were included in this meta-analysis. The onset of sensory block was significantly 40 seconds shorter when dexmedetomidine was added as an adjuvant in the intrathecal injection. The duration of stable sensory block, duration of overall sensory block, and the time before the need for analgesic requirements were significantly extended, 10.8 minutes, 22.3 minutes, and 38.6 minutes, respectively, when dexmedetomidine was used as an adjuvant to local anesthetics (bupivacaine or ropivacaine). No significant differences were detected in the motor block characteristics and the time to achieve peak sensory level between dexmedetomidine and clonidine as adjuvants to local anesthetics. Compared to clonidine, the addition of dexmedetomidine as an adjuvant to local anesthetics is associated with earlier, prolonged sensory block characteristics and later need for analgesic requirements. PMID:26510095

  20. Effect of 50% and maximal inspired oxygen concentrations on respiratory variables in isoflurane-anesthetized horses

    PubMed Central

    2011-01-01

    isoflurane anesthetized horses does not improve oxygenation or oxygen delivery. PMID:21639886

  1. Molecular Insights into the Local Anesthetic Receptor within Voltage-Gated Sodium Channels Using Hydroxylated Analogs of Mexiletine

    PubMed Central

    Desaphy, Jean-François; Dipalma, Antonella; Costanza, Teresa; Carbonara, Roberta; Dinardo, Maria Maddalena; Catalano, Alessia; Carocci, Alessia; Lentini, Giovanni; Franchini, Carlo; Camerino, Diana Conte

    2011-01-01

    , these results confirm our former hypothesis by showing that the presence of hydroxyl groups to the aryloxy moiety of mexiletine greatly reduced sodium channel block, and provide molecular insights into the intimate interaction of local anesthetics with their receptor. PMID:22403541

  2. The comparative genotoxicological study of new local anesthetics, 3-(2-alkoxyphenylcarbamoyloxy)quinuclidium chlorides, on Salmonella typhimurium, Saccharromyces cerevisiae, Vicia faba, Hordeum vulgare and Drosophila melanogaster.

    PubMed

    Miadoková, E; Vlcková, V; Dúhová, V; Trebatická, M; Grolmus, J; Bohmová, B; Podstavková, S; Rauko, P; Plesníková, I; Vlcek, D

    1996-06-01

    Potential gentoxicity of five new local anesthetics, derivatives of phenylcarbamic acid differing in the length of the alkyl chain of the alkoxy substituent, was studied on five test systems. There was a direct relationship with increased toxic effect in bacteria and yeast as a function of the elongation of the alkyl chain of the alkoxy substituents of the phenylcarbamic acid esters. On the other hand, no structure-toxicity relationship was found after application of 3-(2-alkoxyphenylcarbamoyloxy)-quinuclidium chlorides on plants and Drosophila. All anesthetics were nonmutagenic to Salmonella typhimurium strains TA97, TA98, TA100, and TA102 in the absence and in the presence of S9 mix. Pentyloxy and heptyloxy derivatives increased rates of genetic changes in Saccharomyces cerevisiae, mainly revertants at the isoleucine locus. Pentyloxy and hexyloxy derivatives increased the frequency of chromosome aberrations in Vicia faba root-tip meristems. No chlorophyll mutations were detected after treatment of Hordeum vulgare with pentyloxy, hexyloxy and heptyloxy derivatives. No sex-linked recessive lethals were scored in Drosphila melanogaster males. The rates of aneuploids induced in their germ cells were significantly increased after treatment with butoxy and octyloxy derivatives. However, the local toxic and genotoxic effects of test anesthetics on the microorganisms of the anesthetized tissues may be of some importance. In particular, the genotoxic effect exhibited in fungi by the heptyloxy derivative, a potent local anesthetic, was remarkable. PMID:8817059

  3. Local Anesthetic Adjuvants Providing the Longest Duration of Analgesia for Single- Injection Peripheral Nerve Blocks in Orthopedic Surgery: A Literature Review.

    PubMed

    Patacsil, Jason A; McAuliffe, Maura S; Feyh, Leah S; Sigmon, Lorie L

    2016-04-01

    Inadequate pain relief after surgery may delay surgical recovery, decrease patient satisfaction, increase length of stay, raise the risk of hospital readmissions, and increase overall healthcare costs. One way to decrease postoperative pain for patients undergoing orthopedic surgery is through the use of peripheral nerve blocks. Anesthesia providers can add many adjuvants to local anesthetics to improve quality and prolong duration of analgesia. The purpose of this literature review is to evaluate local anesthetic adjuvants to peripheral nerve blocks. A review of published studies using PubMed, MEDLINE, and Cochrane search engines was performed using predefined data fields. Based on this literature review, recommendations for practice are provided. PMID:27311150

  4. Anesthesia with Isoflurane and Sevoflurane in the Crested Serpent Eagle (Spilornis cheela hoya): Minimum Anesthetic Concentration, Physiological Effects, Hematocrit, Plasma Chemistry and Behavioral Effects

    PubMed Central

    CHAN, Fang-Tse; CHANG, Geng-Ruei; WANG, Hsien-Chi; HSU, Tien-Huan

    2013-01-01

    ABSTRACT The initial goal of this study was to determine the minimum anesthetic concentration (MAC) for isoflurane (ISO) and sevoflurane (SEVO) for the crested serpent eagle. Next, we compared the anesthetic effects of each on the physiological effects, hematocrit, plasma chemistry values and behavior in spontaneously breathing captive adult crested serpent eagles. Sixteen eagles were randomly allocated to two groups for anesthesia with ISO (n=8) or SEVO (n=8). First, we measured the MAC values of ISO and SEVO, and four weeks later, we investigated the effect of each on the physiological effects, hematocrit (HCT) and plasma chemistry values. The MAC values of ISO and SEVO for crested serpent eagles were 1.46 ± 0.30 and 2.03 ± 0.32%, respectively. The results revealed no significant differences between the two anesthetics in induction time, while time of extubation to recovery was significantly shorter with SEVO. A time-related increase in end-tidal CO2 and decreases in body temperature and respiratory rates were observed during anesthesia with each anesthetic. There were no significant differences between the effect of the two anesthetics on heart rate, hematocrit, plasma chemistry values or respiration, although each caused minor respiration depression. We concluded that SEVO is a more effective inhalant agent than ISO for use in eagles, showing the most rapidest induction and recovery from anesthesia. PMID:23955396

  5. Effect of addition of magnesium to local anesthetics for peribulbar block: A prospective randomized double-blind study

    PubMed Central

    Sinha, R; Sharma, A; Ray, BR; Chandiran, R; Chandralekha, C; Sinha, R

    2016-01-01

    Background: Magnesium sulphate has been used along with local anesthetics in different regional blocks and found to be effective in decreasing the time of onset of the block and increasing the duration of the block. Objective: To evaluate the effect of addition of magnesium sulfate to standard local anesthetics mixture on the time for onset of the globe and lid akinesia for peribulbar block in ophthalmic surgeries. Materials and Methods: Sixty patients with American Society of Anesthesiologists status I to III undergoing ophthalmic surgery under peribulbar block were included in this study. Patients were randomized into two groups. Both the groups received 4.5 ml of 2% lidocaine, 4.5 ml of 0.5% bupivacaine with150 IU hyaluronidase. Group NS received normal saline 1 ml in the peribulbar block and Group MS, magnesium sulfate 50 mg in 1 ml normal saline. The onset of akinesia, satisfactory block and complications were observed by an independent observer. Results: Demographic data was statistically similar. In the Group NS at 3, 5, 10 and 15 min after the block, complete akinesia was seen in 0, 2, 11 and 28 patients respectively. In the Group MS, at 3, 5, 10 and 15 min after the block, complete akinesia was seen in 13, 23, 27 and 28 patients respectively. Patients received magnesium sulfate showed the statistically significant rapid onset of lid and globe akinesia than the control group till 10 min (P < 0.000). None of the patients needed a supplementary block and had complications during the surgery. Conclusion: Addition of 50 mg of magnesium sulfate to the lidocaine-bupivacaine mixture for peribulbar block decreases the onset of akinesia without any obvious side effect. PMID:26955313

  6. Local anesthetics inhibit kinesin motility and microtentacle protrusions in human epithelial and breast tumor cells.

    PubMed

    Yoon, Jennifer R; Whipple, Rebecca A; Balzer, Eric M; Cho, Edward H; Matrone, Michael A; Peckham, Michelle; Martin, Stuart S

    2011-10-01

    Detached breast tumor cells produce dynamic microtubule protrusions that promote reattachment of cells and are termed tubulin microtentacles (McTNs) due to their mechanistic distinctions from actin-based filopodia/invadopodia and tubulin-based cilia. McTNs are enriched with vimentin and detyrosinated α-tubulin, (Glu-tubulin). Evidence suggests that vimentin and Glu-tubulin are cross-linked by kinesin motor proteins. Using known kinesin inhibitors, Lidocaine and Tetracaine, the roles of kinesins in McTN formation and function were tested. Live-cell McTN counts, adhesion assays, immunofluorescence, and video microscopy were performed to visualize inhibitor effects on McTNs. Viability and apoptosis assays were used to confirm the non-toxicity of the inhibitors. Treatments of human non-tumorigenic mammary epithelial and breast tumor cells with Lidocaine or Tetracaine caused rapid collapse of vimentin filaments. Live-cell video microscopy demonstrated that Tetracaine reduces motility of intracellular GFP-kinesin and causes centripetal collapse of McTNs. Treatment with Tetracaine inhibited the extension of McTNs and their ability to promote tumor cell aggregation and reattachment. Lidocaine showed similar effects but to a lesser degree. Our current data support a model in which the inhibition of kinesin motor proteins by Tetracaine leads to the reductions in McTNs, and provides a novel mechanism for the ability of this anesthetic to decrease metastatic progression. PMID:21069453

  7. The anesthetic interaction of propofol and sevoflurane on the minimum alveolar concentration preventing motor movement (MACNM) in dogs.

    PubMed

    Singsank-Coats, Jill; Seddighi, Reza; Rohrbach, Barton W; Cox, Sherry K; Egger, Christine M; Doherty, Thomas J

    2015-04-01

    The objective of this study was to determine the effects of propofol on the minimum alveolar concentration of sevoflurane needed to prevent motor movement (MAC(NM)) in dogs subjected to a noxious stimulus using randomized crossover design. Six, healthy, adult beagles (9.2 ± 1.3 kg) were used. Dogs were anesthetized with sevoflurane on 3 occasions, at weekly intervals, and baseline MAC(NM) (MAC(NM-B)) was determined on each occasion. Propofol treatments were administered as loading dose (LD) and constant rate infusion (CRI) as follows: Treatment 1 (T1) was 2 mg/kg body weight (BW) and 4.5 mg/kg BW per hour; T2 was 4 mg/kg BW and 9 mg/kg BW per hour; T3 was 8 mg/kg BW and 18 mg/kg BW per hour, respectively. Treatment MAC(NM) (MAC(NM-T)) determination was initiated 60 min after the start of the CRI. Two venous blood samples were collected and combined at each MAC(NM-T) determination for measurement of blood propofol concentration using high-performance liquid chromatography method (HPLC). Data were analyzed using a mixed-model ANOVA and are presented as least square means (LSM) ± standard error of means (SEM). Propofol infusions in the range of 4.5 to 18 mg/kg BW per hour resulted in mean blood concentrations between 1.3 and 4.4 μg/mL, and decreased (P < 0.05) sevoflurane MAC(NM) in a concentration-dependent manner. The percentage decrease in MAC(NM) was 20.5%, 43.0%, and 68.3%, with corresponding blood propofol concentrations of 1.3 ± 0.3 μg/mL, 2.5 ± 0.3 μg/mL, and 4.4 ± 0.3 μg/mL, for T1, T2, and T3, respectively. Venous blood propofol concentrations were strongly correlated (r = 0.855, P < 0.0001) with the decrease in MAC(NM). In dogs, propofol decreased the sevoflurane MAC(NM) in a concentration-dependent manner. PMID:25852224

  8. Randomized Double-Blind Clinical Trial of Eutectic Mixture of Local Anesthetic Creams in Reducing Pain During Hysterosalpingography

    PubMed Central

    Kalantari, Mojgan; Zadeh Modares, Shahrzad; Ahmadi, Firoozeh; Hazari, Vajihe; Haghighi, Hadieh; Chehrazi, Mohammad; Razaghi, Melika

    2014-01-01

    Background: Hysterosalpingography (HSG) is considered as a primary test in infertility work up worldwide due to its reliability in evaluating abnormalities related to the uterus and fallopian tubes. Objectives: To assess the efficacy of applying eutectic mixture of local anesthetics (lidocaine-prilocaine cream) (EMLA) on the uterine cervix in reducing pain during HSG. Patients and Methods: Eighty patients undergoing HSG as part of infertility evaluation were randomly allocated to groups receiving either EMLA (N = 40) or placebo cream (N = 40) in a double-blinded prospective study. Fifteen minutes before HSG, 5 grams of 5% cream was applied to the uterine cervix using a cervical applicator. The degree of pain experienced by the patient was evaluated during and after HSG at five predefined steps on a visual analogue scale (VAS). Results: There was no significant difference in the efficacy between EMLA and placebo creams in pain perception during the entire procedure. There was no significant difference in long term pain perception half an hour after the HSG performance. Conclusions: This study does not support the use of EMLA for HSG. PMID:25780541

  9. Dental Students’ Perception and Anxiety Levels during their First Local Anesthetic Injection

    PubMed Central

    CHANDRASEKARAN, Balamanikandasrinivasan; CUGATI, Navaneetha; KUMARESAN, Ramesh

    2014-01-01

    Background: Student-to-student administration of local anesthesia (LA) has been widely used as the teaching modality to train preclinical dental students. However, studies assessing students’ outlook towards their first injection were limited. Therefore, this study aims to evaluate students’ perception and anxiety levels towards their first LA injection. Methods: Sixty three pre-clinical dental students swapped their roles as both operator and respondents in relation to their first supraperiosteal injection. After being injected, the students conferred their opinion and experiences to the questionnaire based on the five point Likert’s scale and indicated their anxiety levels based on the Interval Scale of Anxiety response (ISAR). Their perception was described using frequencies and percentages and anxiety levels were statistically analysed using one way analysis variance and paired t test. Results: Students learning LA techniques directly on human subjects depicted not only greater confidence in them but also increased anxiety levels. The anxiety levels were found to be high before and during injection in both operator and respondent. Conclusion: The students’ preferred the use of preclinical models rather than student to student administration for their first LA injection exercise. Based on the results obtained, we recommend the need of preclinical simulation model in LA training program. PMID:25897282

  10. β-Cyclodextrin-Propyl Sulfonic Acid Catalysed One-Pot Synthesis of 1,2,4,5-Tetrasubstituted Imidazoles as Local Anesthetic Agents.

    PubMed

    Ran, Yan; Li, Ming; Zhang, Zong-Ze

    2015-01-01

    Some functionalized 1,2,4,5-tetrasubstituted imidazole derivatives were synthesized using a one-pot, four component reaction involving 1,2-diketones, aryl aldehydes, ammonium acetate and substituted aromatic amines. The synthesis has been efficiently carried out in a solvent free medium using β-cyclodextrin-propyl sulfonic acid as a catalyst to afford the target compounds in excellent yields. The local anesthetic effect of these derivatives was assessed in comparison to lidocaine as a standard using a rabbit corneal and mouse tail anesthesia model. The three most potent promising compounds were subjected to a rat sciatic nerve block assay where they showed considerable local anesthetic activity, along with minimal toxicity. Among the tested analogues, 4-(1-benzyl-4,5-diphenyl-1H-imidazol-2-yl)-N,N-dimethylaniline (5g) was identified as most potent analogue with minimal toxicity. It was further characterized by a more favourable therapeutic index than the standard. PMID:26569210

  11. Chip-based nanoelectrospray ionization with Fourier transform mass spectrometric detection to screen for local anesthetics intended to mask limb sore in walking horses.

    PubMed

    Szarka, Szabolcs; Prokai, Laszlo

    2015-03-01

    We report a high-throughput chip-based nanoelectrospray ionization method coupled with Fourier transform mass spectrometry to screen for local anesthetics in samples collected by swabbing. These drugs have been used to mask pain on the limbs of walking horses after forbidden practices of soring or physical abuse. Optimized for lidocaine, the method afforded sub-ppm mass accuracy for nine local anesthetics included in the study. From doped cotton swabs, two third and all of the analytes were detected after adding 10 ng and 100 ng of each drug, respectively. Benzocaine and/or lidocaine were found on positive swab samples collected during walking horse competitions. PMID:25800188

  12. Local anesthetic bupivacaine induced ovarian and prostate cancer apoptotic cell death and underlying mechanisms in vitro.

    PubMed

    Xuan, Wei; Zhao, Hailin; Hankin, James; Chen, Lin; Yao, Shanglong; Ma, Daqing

    2016-01-01

    Retrospective studies indicate that the use of regional anesthesia can reduce cancer recurrence after surgery which could be due to ranging from immune function preservation to direct molecular mechanisms. This study was to investigate the effects of bupivacaine on ovarian and prostate cancer cell biology and the underlying molecular mechanisms. Cell viability, proliferation and migration of ovarian carcinoma (SKOV-3) and prostate carcinoma (PC-3) were examined following treatment with bupivacaine. Cleaved caspase 3, 8 and 9, and GSK-3β, pGSK-3β(tyr216) and pGSK-3β(ser9) expression were assessed by immunofluorescence. FAS ligand neutralization, caspase and GSK-3 inhibitors and GSK-3β siRNA were applied to further explore underlying mechanisms. Clinically relevant concentrations of bupivacaine reduced cell viability and inhibited cellular proliferation and migration in both cell lines. Caspase 8 and 9 inhibition generated partial cell death reversal in SKOV-3, whilst only caspase 9 was effective in PC-3. Bupivacaine increased the phosphorylation of GSK-3β(Tyr216) in SKOV-3 but without measurable effect in PC3. GSK-3β inhibition and siRNA gene knockdown decreased bupivacaine induced cell death in SKOV-3 but not in PC3. Our data suggests that bupivacaine has direct 'anti-cancer' properties through the activation of intrinsic and extrinsic apoptotic pathways in ovarian cancer but only the intrinsic pathway in prostate cancer. PMID:27195613

  13. Local anesthetic bupivacaine induced ovarian and prostate cancer apoptotic cell death and underlying mechanisms in vitro

    PubMed Central

    Xuan, Wei; Zhao, Hailin; Hankin, James; Chen, Lin; Yao, Shanglong; Ma, Daqing

    2016-01-01

    Retrospective studies indicate that the use of regional anesthesia can reduce cancer recurrence after surgery which could be due to ranging from immune function preservation to direct molecular mechanisms. This study was to investigate the effects of bupivacaine on ovarian and prostate cancer cell biology and the underlying molecular mechanisms. Cell viability, proliferation and migration of ovarian carcinoma (SKOV-3) and prostate carcinoma (PC-3) were examined following treatment with bupivacaine. Cleaved caspase 3, 8 and 9, and GSK-3β, pGSK-3βtyr216 and pGSK-3βser9 expression were assessed by immunofluorescence. FAS ligand neutralization, caspase and GSK-3 inhibitors and GSK-3β siRNA were applied to further explore underlying mechanisms. Clinically relevant concentrations of bupivacaine reduced cell viability and inhibited cellular proliferation and migration in both cell lines. Caspase 8 and 9 inhibition generated partial cell death reversal in SKOV-3, whilst only caspase 9 was effective in PC-3. Bupivacaine increased the phosphorylation of GSK-3βTyr216 in SKOV-3 but without measurable effect in PC3. GSK-3β inhibition and siRNA gene knockdown decreased bupivacaine induced cell death in SKOV-3 but not in PC3. Our data suggests that bupivacaine has direct ‘anti-cancer’ properties through the activation of intrinsic and extrinsic apoptotic pathways in ovarian cancer but only the intrinsic pathway in prostate cancer. PMID:27195613

  14. Short Term Results After Local Application of Steroids and Anesthetics in Patients with Painful Spine Conditions

    PubMed Central

    Hadziahmetovic, Narcisa Vavra; Aganovic, Damir; Kadic, Aldijana; Biscevic, Mirza

    2014-01-01

    ABSTRACT Introduction: Spinal pain is the most common of all chronic pain disorders. Imaging studies can be used to determine whether a pathological process is associated with the patient’s symptoms. Objective: To determine the short-term efficiency of local instillation of steroids in patients with painful spine conditions. Materials and methods: A prospective study included 35 patients with diagnosis of lumbar or cervical radiculopathy, or cervical and lumbar syndrome at the Department for the Physical Medicine and Rehabilitation, Department for the Orthopedics and Traumatology, and Department for the Neurosurgery, Clinical Canter University of Sarajevo (KCUS). A clinical examination, visual pain scale (VAS) and Oswestry Disability Index (ODI) were performed prior to the needle procedure and seven days after it. Descriptive and comparative statistics were used for comparison of pre and post-interventional results. This procedure was done for the first time in our region. Results: The males and females were equally represented in this study (17:18). The patients were 29 to 80 years old. The highest number of patients have been between 40-60 years, older then that have been 44,2% of patients, and younger only 8,5%. Patients have complained about the radicular pain along the legs or arms or back or neck pain. Most of them had disc herniation–57,14%, 8,57% had bulging disc, 8,57% had spinal canal stenosis, 5,71% had fasetarthrosis, rest of them had combination of those conditions. There was a statistically significant difference between the value of ODI score before procedure and 7 days later (26±10:16±12; p<0,001). The difference was also statistically significant in VAS values (7±1:1±1; p <0,001). Discussion: Our study suggests that needle instillation of steroid and lidocaine is effective in short-term pain occurs in different painful spine conditions (Sy cervicale, lumbare and radiculopathy). It is valuable alternative to the classic methods of physical

  15. Comparative evaluation of endodontic pressure syringe, insulin syringe, jiffy tube, and local anesthetic syringe in obturation of primary teeth: An in vitro study

    PubMed Central

    Hiremath, Mallayya C.; Srivastava, Pooja

    2016-01-01

    Purpose: The purpose of this in vitro study was to compare four methods of root canal obturation in primary teeth using conventional radiography. Materials and Methods: A total of 96 root canals of primary molars were prepared and obturated with zinc oxide eugenol. Obturation methods compared were endodontic pressure syringe, insulin syringe, jiffy tube, and local anesthetic syringe. The root canal obturations were evaluated by conventional radiography for the length of obturation and presence of voids. The obtained data were analyzed using Chi-square test. Results: The results showed significant differences between the four groups for the length of obturation (P < 0.05). The endodontic pressure syringe showed the best results (98.5% optimal fillings) and jiffy tube showed the poor results (37.5% optimal fillings) for the length of obturation. The insulin syringe (79.2% optimal fillings) and local anesthetic syringe (66.7% optimal fillings) showed acceptable results for the length of root canal obturation. However, minor voids were present in all the four techniques used. Conclusions: Endodontic pressure syringe produced the best results in terms of length of obturation and controlling paste extrusion from the apical foramen. However, insulin syringe and local anesthetic syringe can be used as effective alternative methods. PMID:27433062

  16. Multimodal analgesia with gabapentin and local anesthetics prevents acute and chronic pain after breast surgery for cancer.

    PubMed

    Fassoulaki, Argyro; Triga, Argyro; Melemeni, Aikaterini; Sarantopoulos, Constantine

    2005-11-01

    We evaluated the effect of multimodal analgesia on acute and chronic pain after breast surgery for cancer. Fifty patients scheduled for breast cancer surgery were blindly randomized to receive gabapentin, eutectic mixture of local anesthetics cream, and ropivacaine in the wound or three placebos. Pain (visual analog scale) and analgesics were recorded in the postanesthesia care unit (PACU) 3, 6, and 9 h and 8 days after surgery. Three and 6 mo later, patients were assessed for chronic pain. The treatment group consumed less paracetamol in the PACU (469 versus 991 mg; P < 0.002) and less Lonalgal (1.0 versus 4.4 tablets; P = 0.003) than the controls, exhibited lower visual analog scale scores at rest in the PACU (P = 0.001) and on postoperative Days 1, 3, and 5 (P = 0.040, P = 0.015, and P = 0.045, respectively), and after movement in the PACU (P = 0.001) and on postoperative Days 2, 4, and 8 (P = 0.028, P = 0.007, and P = 0.032, respectively). Three and 6 mo after surgery, 18 of 22 (82%) and 12 of 21 (57%) of the controls reported chronic pain versus 10 of 22 (45%) and 6 of 20 (30%) in the treatment group (P = 0.028 and P = 0.424, respectively); 5 of 22 and 4 of 21 of the controls required analgesics versus 0 of 22 and 0 of 20 of those treated (P = 0.048 and P = 0.107, respectively). Multimodal analgesia reduced acute and chronic pain after breast surgery for cancer. PMID:16244006

  17. Comparison of eutectic mixture of local anesthetics cream with dorsal penile nerve block using lignocaine for circumcision in infants

    PubMed Central

    Mujeeb, Sabeen; Akhtar, Jamshed; Ahmed, Soofia

    2013-01-01

    Objective: Circumcision is a commonly performed surgical procedure but choice of anesthesia remained an issue of research and debate. This study was conducted to find out the effectiveness of the eutectic mixture of local anesthetic (EMLA) cream with dorsal penile nerve block (DPNB) using lignocaine, for reduction of pain during circumcision. Methodology: This was comparative study carried out in Surgical Unit B of National Institute of Child Health Karachi, from May 2008 to October 2008. Patients under six month of age were randomized in to two groups (EMLA and DPNB) of fifty patients each. The effectiveness of pain control was assessed by measuring the baseline heart rate (HR), respiratory rate (RR) and Neonatal infant Pain Scale (NIPS scale) before the start of procedure and measuring of these parameters for each step of circumcision. Independent sample t -test was used to compare means and repeated ANOVA was used to compare means of HR, RR, oxygen (O2) saturations and NIPS. Results: The mean age in both the groups was 2.3 months. There was no statistically significant difference in baseline parameters in both the groups except the respiratory rate, which was significantly raised in DPNB group (33 breaths/min in EMLA and 38 in DPNB P < 0.04). During circumcision there was significant increase in heart rate in DPNB group, especially in step three and step four (p < 0.04). Oxygen saturation dropped in both the groups (baseline saturation 98% up to 91% in step 4). While assessing NIPS scores in both the groups, statistically significant difference was found between NIPS at step two and step four in two groups (p < 0.04). Conclusions: The overall pain control was equal in both the groups, although NIPS score was higher in DPNB in step two and four of circumcision. There was difference in application and cost. EMLA was easy to apply but has increased cost; while DPNB required expertise. PMID:24353502

  18. Effects of Methadone on the Minimum Anesthetic Concentration of Isoflurane, and Its Effects on Heart Rate, Blood Pressure and Ventilation during Isoflurane Anesthesia in Hens (Gallus gallus domesticus)

    PubMed Central

    Pypendop, Bruno Henri; Zangirolami Filho, Darcio; Sousa, Samuel Santos; Valadão, Carlos Augusto Araújo

    2016-01-01

    The aim of this study was to measure the temporal effects of intramuscular methadone administration on the minimum anesthetic concentration (MAC) of isoflurane in hens, and to evaluate the effects of the isoflurane-methadone combination on heart rate and rhythm, blood pressure and ventilation. Thirteen healthy adult hens weighing 1.7 ± 0.2 kg were used. The MAC of isoflurane was determined in each individual using the bracketing method. Subsequently, the reduction in isoflurane MAC produced by methadone (3 or 6 mg kg-1, IM) was determined by the up-and-down method. Stimulation was applied at 15 and 30 minutes, and at 45 minutes if the bird had not moved at 30 minutes. Isoflurane MAC reduction was calculated at each time point using logistic regression. After a washout period, birds were anesthetized with isoflurane and methadone, 6 mg kg-1 IM was administered. Heart rate and rhythm, respiratory rate, blood gas values and invasive blood pressure were measured at 1.0 and 0.7 isoflurane MAC, and during 45 minutes after administration of methadone once birds were anesthetized with 0.7 isoflurane MAC. Fifteen minutes after administration of 3 mg kg-1 of methadone, isoflurane MAC was reduced by 2 (-9 to 13)% [logistic regression estimate (95% Wald confidence interval)]. Administration of 6 mg kg-1 of methadone decreased isoflurane MAC by 29 (11 to 46)%, 27 (-3 to 56)% and 10 (-8 to 28)% after 15, 30 and 45 minutes, respectively. Methadone (6 mg kg-1) induced atrioventricular block in three animals and ventricular premature contractions in two. Methadone caused an increase in arterial blood pressure and arterial partial pressure of carbon dioxide, while heart rate and pH decreased. Methadone, 6 mg kg-1 IM significantly reduced isoflurane MAC by 30% in hens 15 minutes after administration. At this dose, methadone caused mild respiratory acidosis and increase in systemic blood pressure. PMID:27018890

  19. Low flow oxygen therapy from a portable oxygen concentrator or an oxygen cylinder effectively treats hypoxemia in anesthetized white-tailed deer (Odocoileus virginianus).

    PubMed

    Fahlman, Asa; Caulkett, Nigel; Woodbury, Murray; Duke-Novakovski, Tanya; Wourms, Vincent

    2014-06-01

    For treatment of hypoxemia, delivery of the minimum effective oxygen flow rate is advantageous during field anesthesia because it prolongs the life of the oxygen cylinder. Portable oxygen concentrators as the oxygen source require less logistical considerations than cylinders and are a safer alternative during helicopter field work because they are nonexplosive devices. The objective of this study was to evaluate low oxygen flow rates by continuous or pulsed intranasal delivery for treatment of hypoxemia in anesthetized white-tailed deer (Odocoileus virginianus). Nine captive adult female deer (body mass 56-72 kg) were physically restrained in a drop-floor chute and hand injected intramuscularly with medetomidine (0.1-0.14 mg/kg) and ketamine (2.5-4.3 mg/kg). Intranasal oxygen was delivered from an oxygen cylinder at continuous flow rates of 1 and 2 L/min or from a battery driven oxygen concentrator (EverGo Portable Oxygen Concentrator, Respironics) with pulse-dose delivery (maximum capacity of 1.05 L/min). The pulse-dose setting (pulse volume 12-70 ml) was adjusted according to the respiratory rate. Arterial blood gases were analyzed before, during, and after O2 supplementation. A 10-min washout period was allowed between treatment groups. All three treatments adequately treated hypoxemia. The partial pressure of arterial oxygenation increased significantly from baseline values of 55 +/- 10 to 115 +/- 31 mm Hg during supplementation from the oxygen concentrator, to 138 +/- 21 mm Hg during supplementation from the oxygen cylinder at 1 L/min, and to 201 +/- 42 mm Hg at 2 L/min. In conclusion, low flow rates of intranasal oxygen supplemented continuously from an oxygen cylinder or by pulsed delivery from a portable oxygen concentrator effectively treated hypoxemia in anesthetized white-tailed deer. PMID:25000687

  20. Absolute determination of local tropospheric OH concentrations

    NASA Technical Reports Server (NTRS)

    Armerding, Wolfgang; Comes, Franz-Josef

    1994-01-01

    Long path absorption (LPA) according to Lambert Beer's law is a method to determine absolute concentrations of trace gases such as tropospheric OH. We have developed a LPA instrument which is based on a rapid tuning of the light source which is a frequency doubled dye laser. The laser is tuned across two or three OH absorption features around 308 nm with a scanning speed of 0.07 cm(exp -1)/microsecond and a repetition rate of 1.3 kHz. This high scanning speed greatly reduces the fluctuation of the light intensity caused by the atmosphere. To obtain the required high sensitivity the laser output power is additionally made constant and stabilized by an electro-optical modulator. The present sensitivity is of the order of a few times 10(exp 5) OH per cm(exp 3) for an acquisition time of a minute and an absorption path length of only 1200 meters so that a folding of the optical path in a multireflection cell was possible leading to a lateral dimension of the cell of a few meters. This allows local measurements to be made. Tropospheric measurements have been carried out in 1991 resulting in the determination of OH diurnal variation at specific days in late summer. Comparison with model calculations have been made. Interferences are mainly due to SO2 absorption. The problem of OH self generation in the multireflection cell is of minor extent. This could be shown by using different experimental methods. The minimum-maximum signal to noise ratio is about 8 x 10(exp -4) for a single scan. Due to the small size of the absorption cell the realization of an open air laboratory is possible in which by use of an additional UV light source or by additional fluxes of trace gases the chemistry can be changed under controlled conditions allowing kinetic studies of tropospheric photochemistry to be made in open air.

  1. Enhancement of the 1-Octanol/Water Partition Coefficient of the Anti-Inflammatory Indomethacin in the Presence of Lidocaine and Other Local Anesthetics.

    PubMed

    Tateuchi, Ryo; Sagawa, Naoki; Shimada, Yohsuke; Goto, Satoru

    2015-07-30

    Side effects and excessive potentiation of drug efficacy caused by polypharmacy are becoming important social issues. The apparent partition coefficient of indomethacin (log P'IND) increases in the presence of lidocaine, and this is used as a physicochemical model for investigating polypharmacy. We examined the changes in log P'IND caused by clinically used local anesthetics-lidocaine, tetracaine, mepivacaine, bupivacaine, and dibucaine-and by structurally similar basic drugs-procainamide, imipramine, and diltiazem. The quantitative structure-activity relationship study of log P'IND showed that the partition coefficient values (log PLA) and the structural entropic terms (ΔSobs, log f) of the additives affect log P'IND. These results indicate that the local anesthetics and structurally similar drugs function as phase-transfer catalysts, increasing the membrane permeability of indomethacin via heterogeneous intermolecular association. Therefore, we expect that the potency of indomethacin, an acidic nonsteroidal anti-inflammatory drug, will be increased by concurrent administration of the other drugs. PMID:26121007

  2. Modulation of high- and low-frequency components of the cortical local field potential via nicotinic and muscarinic acetylcholine receptors in anesthetized mice

    PubMed Central

    Waters, Jack

    2013-01-01

    Release of acetylcholine (ACh) in neocortex is important for learning, memory and attention tasks. The primary source of ACh in neocortex is axons ascending from the basal forebrain. Release of ACh from these axons evokes changes in the cortical local field potential (LFP), including a decline in low-frequency spectral power that is often referred to as desynchronization of the LFP and is thought to result from the activation of muscarinic ACh receptors. Using channelrhodopsin-2, we selectively stimulated the axons of only cholinergic basal forebrain neurons in primary somatosensory cortex of the urethane-anesthetized mouse while monitoring the LFP. Cholinergic stimulation caused desynchronization and two brief increases in higher-frequency power at stimulus onset and offset. Desynchronization (1–6 Hz) was localized, extending ≤ 1 mm from the edge of stimulation, and consisted of both nicotinic and muscarinic receptor-mediated components that were inhibited by mecamylamine and atropine, respectively. Hence we have identified a nicotinic receptor-mediated component to desynchronization. The increase in higher-frequency power (>10 Hz) at stimulus onset was also mediated by activation of nicotinic and muscarinic receptors. However, the increase in higher-frequency power (10–20 Hz) at stimulus offset was evoked by activation of muscarinic receptors and inhibited by activation of nicotinic receptors. We conclude that the activation of nicotinic and muscarinic ACh receptors in neocortex exerts several effects that are reflected in distinct frequency bands of the cortical LFP in urethane-anesthetized mice. PMID:24155009

  3. Cartridge syringe vs computer controlled local anesthetic delivery system: Pain related behaviour over two sequential visits – a randomized controlled trial

    PubMed Central

    Thoppe-Dhamodhara, Yogesh-Kumar; Asokan, Sharath; John, Baby-John; Pollachi-Ramakrishnan, GeethaPriya; Ramachandran, Punithavathy; Vilvanathan, Praburajan

    2015-01-01

    Background Local anesthetic injection is one of the most anxiety provoking procedure in dentistry. Knowledge about change in pain related behaviour during consecutive visits helps in and scheduling of treatment procedures and management of children in dental clinic. Aim To compare the pain perception, behavioural response and the associated change in physiological parameters while receiving local anesthesia injection with cartridge syringe and computer controlled local anesthetic delivery system (CCLAD) over two consecutive visits. Material and Methods In this randomized controlled cross over trial, 120 children aged 7 – 11 years were randomly divided into group A: receiving injections with CCLAD during first visit; group B: receiving injections with cartridge syringe during first visit. The physiological parameters (heart rate and blood pressure) were recorded before and during injection procedure. Objective evaluation of disruptive behaviour and subjective evaluation of pain perceived were done using Face Legs Activity Cry Consolability (FLACC) scale and modified facial image scale (FIS) respectively. Results No statistical difference in pain response (p= 0.164) and disruptive behaviour (p = 0.120) between cartridge syringe and CCLAD injections were seen during the first visit although the latter showed lesser scores. However, during the second visit there were significant increase in pain response (p = 0.004) and disruptive behaviour (p = 0.006) in cartridge syringe group with an associated increase in heart rate. Conclusions Injections with CCLAD produced lesser pain ratings and disruptive behaviour than cartridge syringe in children irrespective of order of visit. Key words:Behaviour, cartridge syringe, CCLAD, local anesthesia. PMID:26535099

  4. Toward Localized In Vivo Biomarker Concentration Measurements

    PubMed Central

    Zhang, Xiaojuan; Reeves, Daniel; Shi, Yipeng; Gimi, Barjor; Nemani, Krishnamurthy V.; Perreard, Irina M.; Toraya-Brown, Seiko; Fiering, Steven; Weaver, John B.

    2015-01-01

    We know a great deal about the biochemistry of cells because they can be isolated and studied. The biochemistry of the much more complex in vivo environment is more difficult to study because the only ways to quantitate concentrations is to sacrifice the animal or biopsy the tissue. Either method disrupts the environment profoundly and neither method allows longitudinal studies on the same individual. Methods of measuring chemical concentrations in vivo are very valuable alternatives to sacrificing groups of animals. We are developing microscopic magnetic nanoparticle (mNP) probes to measure the concentration of a selected molecule in vivo. The mNPs are targeted to bind the selected molecule and the resulting reduction in rotational freedom can be quantified remotely using magnetic spectroscopy. The mNPs must be contained in micrometer sized porous shells to keep them from migrating and to protect them from clearance by the immune system. There are two key issues in the development of the probes. First, we demonstrate the ability to measure concentrations in the porous walled alginate probes both in phosphate buffered saline and in blood, which is an excellent surrogate for the complex and challenging in vivo environment. Second, sensitivity is critical because it allows microscopic probes to measure very small concentrations very far away. We report sensitivity measurements on recently introduced technology that has allowed us to improve the sensitivity by two orders of magnitude, a factor of 200 so far. PMID:26203196

  5. A new look at the hemolytic effect of local anesthetics, considering their real membrane/water partitioning at pH 7.4.

    PubMed

    Malheiros, Sônia V P; Pinto, Luciana M A; Gottardo, Luciane; Yokaichiya, Daniela K; Fraceto, Leonardo F; Meirelles, Nilce C; de Paula, Eneida

    2004-08-01

    The interaction of local anesthetics (LA) with biological and phospholipid bilayers was investigated regarding the contribution of their structure and physicochemical properties to membrane partition and to erythrocyte solubilization. We measured the partition into phospholipid vesicles-at pH 5.0 and 10.5-and the biphasic hemolytic effect on rat erythrocytes of: benzocaine, chloroprocaine, procaine, tetracaine, bupivacaine, mepivacaine, lidocaine, prilocaine, and dibucaine. At pH 7.4, the binding of uncharged and charged LA to the membranes was considered, since it results in an ionization constant (pK(app)) different from that observed for the anesthetic in the aqueous phase (pK(w)). Even though it occurred at a pH at which there is a predominance of the charged species, hemolysis was greatly influenced by the uncharged species, revealing that the disrupting effect of LA on these membranes is mainly a consequence of hydrophobic interactions. The correlation between the hemolytic activity and the LA potency shows that hemolytic experiments could be used for the prediction of activity in the development of new LA molecules. PMID:15228957

  6. Long-Acting Local Anesthetics in Oral Surgery: An Experimental Evaluation of Bupivacaine and Etidocaine for Infiltration Anesthesia

    PubMed Central

    Danielsson, Karlhâkan; Evers, Hans; Nordenram, Åke

    1985-01-01

    The effect of bupivacaine 7.5 mg/ml with epinephrine 5μg/ml, etidocaine 15 mg/ml with epinephrine 5 μg/ml, and lidocaine 20 mg/ml with epinephrine 12.5 μg/ml was studied when used for oral infiltration anesthesia. Twenty healthy volunteers took part in the experimental and double-blind study. One ml of the respective anesthetic solution was deposited supraperiosteally in the apical area of the maxillary right lateral incisor. Onset time, frequency of analgesia, gingival spread, and duration of tooth analgesia were studied and duration of soft-tissue numbness registered. The present investigation showed that lidocaine had a shorter onset time compared with bupivacaine. No difference with regard to frequency was found. Bupivacaine and etidocaine had a longer period of soft-tissue numbness, but a significantly shorter duration of tooth analgesia than lidocaine. PMID:3859232

  7. [Local anesthesia in the children undergoing the fibroendoscopic study of the nasal cavity, nasopharynx, and larynx: are topical anesthetics needed?].

    PubMed

    Soldatsky, Yu L; Denisova, O A; Mazur, E M

    2015-01-01

    This prospective randomized study with double blind control was designed to evaluate the effectiveness of various anesthetic techniques employed prior to fibroendoscopy of the nose, nasopharynx, and larynx of the children. The study included 160 children at the age varying from 3 to 14 (mean 7.4±2.96) years randomly allocated to four statistically comparable groups matched for age and sex. The following preparations were used to treat the children prior to fibroendoscopy: physiological solution (group 1), a 0.05% xylometazoline solution (group 2), a 10% lidocaine solution (group 3), and a mixture of 0.05% xylometazoline and 10% lidocaine solutions (group 4). The evaluation of the tolerance to the pretreatment of the nasal cavity with lidocaine and lidocaine plus xylometazoline (groups 3 and 4) showed that it was significantly (p<0.05) worse than in groups 1 and 2. The subjective tolerance to fibroendoscopy as reported by the patients was on the average similar in the children of all four groups (p>0.05). The doctors found the tolerance of fibroendoscopy to be the worst following pretreatment with the physiological solution (group 1) and the best after pretreatment with a mixture of lidocaine and xylometazoline (group 4) (p=0.03). The children comprising groups 2 and 3 were not significantly different in terms of the tolerance to fibroendoscopy (p>0.05). It is concluded that the pretreatment of the nasal cavity of the children with a 10% lidocaine solution before fibroendoscopy has no advantage over the pretreatment with a 0.05% xylometazoline solution; at the same time, insuflation of lidocaine as an anesthetic induces more pronounced negative emotions compared with the application of 0.05% xylometazoline. PMID:26525473

  8. Benzocaine as an anesthetic for striped bass

    USGS Publications Warehouse

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

    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.

  9. Comparative cardiac electrophysiologic study of PK 10139, a new antiarrhythmic agent, and quinidine in anesthetized dogs: plasma concentration-response relationships.

    PubMed

    Heckle, J; Jaillon, P; Jozefczak, C; Cheymol, G

    1985-01-01

    Cardiac electrophysiologic effects of PK 10139 (PK), a new quinoleic antiarrhythmic agent, were compared with those of quinidine sulphate (Q) after three cumulative intravenous doses of 0.75, 1.5, and 3 mg/kg of PK and 5, 10, and 20 mg/kg of Q in anesthetized dogs. A control group of animals received saline solution only. Both PK and Q provoked an increase, correlated with plasma concentrations, in atrionodal (St-H), His-Purkinje system (HV), and auriculoventricular (QS) conduction times, and auricular effective and functional refractory periods (AERP, AFRP). The effects of PK on conduction times were more marked than those of Q. Slopes of the plasma concentration-effect curves were similar for the two drugs for HV and QS but different for St-H. PK was 42.5 times more potent than Q in increasing HV and 46 times more potent than Q in increasing QS. Effects of PK on AFRP and nodal FRP did not differ from those observed in control animals. These findings demonstrate more marked effects of PK, when compared with Q, at doses 6.7 times lower and at plasma concentrations 15 to 42 times less, without chronotropic effects or significant alterations in blood pressure, and without adverse reactions on the central nervous system. PMID:2580140

  10. Comparison of cardiorespiratory variables in dorsally recumbent horses anesthetized with guaifenesin-ketamine-xylazine spontaneously breathing 50% or maximal oxygen concentrations.

    PubMed

    Karrasch, Nicole M; Hubbell, John A E; Aarnes, Turi K; Bednarski, Richard M; Lerche, Phillip

    2015-04-01

    This study compared cardiorespiratory variables in dorsally recumbent horses anesthetized with guaifenesin-ketamine-xylazine and spontaneously breathing 50% or maximal (> 90%) oxygen (O2) concentrations. Twelve healthy mares were randomly assigned to breathe 50% or maximal O2 concentrations. Horses were sedated with xylazine, induced to recumbency with ketamine-diazepam, and anesthesia was maintained with guaifenesin-ketamine-xylazine to effect. Heart rate, arterial blood pressures, respiratory rate, lithium dilution cardiac output (CO), inspired and expired O2 and carbon dioxide partial pressures, and tidal volume were measured. Arterial and mixed-venous blood samples were collected prior to sedation (baseline), during 30 minutes of anesthesia, 10 minutes after disconnection from O2, and 30 minutes after standing. Shunt fraction, O2 delivery, and alveolar-arterial O2 partial pressures difference [P(A-a)O2] were calculated. Recovery times were recorded. There were no significant differences between groups in cardiorespiratory parameters or in P(A-a)O2 at baseline or 30 minutes after standing. Oxygen partial pressure difference in the 50% group was significantly less than in the maximal O2 group during anesthesia. PMID:25829559

  11. Comparison of cardiorespiratory variables in dorsally recumbent horses anesthetized with guaifenesin-ketamine-xylazine spontaneously breathing 50% or maximal oxygen concentrations

    PubMed Central

    Karrasch, Nicole M.; Hubbell, John A.E.; Aarnes, Turi K.; Bednarski, Richard M.; Lerche, Phillip

    2015-01-01

    This study compared cardiorespiratory variables in dorsally recumbent horses anesthetized with guaifenesin-ketamine-xylazine and spontaneously breathing 50% or maximal (> 90%) oxygen (O2) concentrations. Twelve healthy mares were randomly assigned to breathe 50% or maximal O2 concentrations. Horses were sedated with xylazine, induced to recumbency with ketamine-diazepam, and anesthesia was maintained with guaifenesin-ketamine-xylazine to effect. Heart rate, arterial blood pressures, respiratory rate, lithium dilution cardiac output (CO), inspired and expired O2 and carbon dioxide partial pressures, and tidal volume were measured. Arterial and mixed-venous blood samples were collected prior to sedation (baseline), during 30 minutes of anesthesia, 10 minutes after disconnection from O2, and 30 minutes after standing. Shunt fraction, O2 delivery, and alveolar-arterial O2 partial pressures difference [P(A-a)O2] were calculated. Recovery times were recorded. There were no significant differences between groups in cardiorespiratory parameters or in P(A-a)O2 at baseline or 30 minutes after standing. Oxygen partial pressure difference in the 50% group was significantly less than in the maximal O2 group during anesthesia. PMID:25829559

  12. Improving entanglement concentration of Gaussian states by local displacements

    SciTech Connect

    Fiurasek, Jaromir

    2011-07-15

    We investigate entanglement concentration of continuous-variable Gaussian states by local single-photon subtractions combined with local Gaussian operations. We first analyze the local squeezing-enhanced entanglement-concentration protocol proposed very recently by Zhang and van Loock [arXiv:1103.4500] and discuss the mechanism by which local squeezing before photon subtraction helps to increase the entanglement of the output state of the protocol. We next show that a similar entanglement improvement can be achieved by using local coherent displacements instead of single-mode squeezing.

  13. Children's behavioral pain reactions during local anesthetic injection using cotton-roll vibration method compared with routine topical anesthesia: A randomized controlled trial

    PubMed Central

    Bagherian, Ali; Sheikhfathollahi, Mahmood

    2016-01-01

    Background: Topical anesthesia has been widely advocated as an important component of atraumatic administration of intraoral local anesthesia. The aim of this study was to use direct observation of children's behavioral pain reactions during local anesthetic injection using cotton-roll vibration method compared with routine topical anesthesia. Materials and Methods: Forty-eight children participated in this randomized controlled clinical trial. They received two separate inferior alveolar nerve block or primary maxillary molar infiltration injections on contralateral sides of the jaws by both cotton-roll vibration (a combination of topical anesthesia gel, cotton roll, and vibration for physical distraction) and control (routine topical anesthesia) methods. Behavioral pain reactions of children were measured according to the author-developed face, head, foot, hand, trunk, and cry (FHFHTC) scale, resulting in total scores between 0 and 18. Results: The total scores on the FHFHTC scale ranged between 0-5 and 0-10 in the cotton-roll vibration and control methods, respectively. The mean ± standard deviation values of total scores on FHFHTC scale were lower in the cotton-roll vibration method (1.21 ± 1.38) than in control method (2.44 ± 2.18), and this was statistically significant (P < 0.001). Conclusion: It may be concluded that the cotton-roll vibration method can be more helpful than the routine topical anesthesia in reducing behavioral pain reactions in children during local anesthesia administration. PMID:27274349

  14. Comparative, double-blind, controlled study of intra-articular hyaluronic acid (Hyalubrix®) injections versus local anesthetic in osteoarthritis of the hip

    PubMed Central

    2009-01-01

    Introduction Comparison of intra-articular bacterial-derived hyaluronic acid (Hyalubrix®) (HA) with local analgesia (mepivacaine) for osteoarthritis (OA) of the hip. Methods A pilot prospective, double-blind, 6-month randomized trial of 42 patients with hip OA. HA or mepivacaine was administered twice (once a month) under ultrasound guidance. Efficacy measurements included the Lequesne's algofunctional index, a visual analog scale for pain, concomitant use of analgesia, patient and physician global measurement, and safety. Results Patients in the HA group exhibited a significantly reduced Lequesne's algofunctional index 3 and 6 months after treatment (P < 0.001) and significantly reduced visual analog scale pain scores 3 and 6 months after treatment (P < 0.05) compared with the local anesthetic group. All primary and secondary measures were significantly improved versus baseline, but other than the above were not different from each other at 3 or 6 months. Adverse effects were minimal. Conclusions This comparative study suggests a beneficial effect and safety of intra-articular HA in the management of hip OA. Trial registration number ISRCTN39397064. PMID:20003205

  15. Suppression of postoperative pain by the combination of a nonsteroidal anti-inflammatory drug, flurbiprofen, and a long-acting local anesthetic, etidocaine.

    PubMed

    Dionne, R A; Wirdzek, P R; Fox, P C; Dubner, R

    1984-04-01

    The analgesic efficacy of the combination of a nonsteroidal anti-inflammatory drug, flurbiprofen, and a long-acting local anesthetic, etidocaine, was evaluated for the suppression of acute postoperative pain. Subjects having two impacted third molars removed at two appointments received either the experimental combination or standard treatment in a randomized, crossover design. The experimental treatment consisted of 100 mg flurbiprofen 30 minutes before surgery, 1.5% etidocaine with 1:200,000 epinephrine five minutes before surgery, and 100 mg flurbiprofen three hours after surgery. Standard treatment consisted of 10 mg oxycodone plus 650 mg acetaminophen 30 minutes before surgery, 2% lidocaine with 1:100,000 epinephrine five minutes before surgery, and a second dose of the oxycodone-acetaminophen combination three hours after surgery. Pain intensity was rated hourly from one to seven hours after surgery, using a variety of ordinal and analog scales. The flurbiprofen-etidocaine combination resulted in significantly less postoperative pain than the oxycodone plus acetaminophen-lidocaine combination on all four analgesic scales used and was preferred by the majority of the patients. This study shows that pretreatment with a nonsteroidal anti-inflammatory drug, flurbiprofen, in combination with a long-acting local analgesic, etidocaine, suppresses pain to a greater extent than a potent opiate mild/analgesic combination and lidocaine without an increase in side-effect liability. PMID:6586802

  16. Minimum effective local anesthetic volume for surgical anesthesia by subparaneural, ultrasound-guided popliteal sciatic nerve block: A prospective dose-finding study.

    PubMed

    Bang, Seung Uk; Kim, Dong Ju; Bae, Jin Ho; Chung, Kyudon; Kim, Yeesuk

    2016-08-01

    Because of its rapid onset time, recent years have seen an increase in the use of ultrasound (US)-guided popliteal sciatic nerve block (PSNB) via subparaneural injection for induction of surgical anesthesia. Moreover, in below-knee surgery, combined blocks, as opposed to sciatic nerve block alone, have become more common. These combined blocks often require a large volume of local anesthetic (LA), thus increasing the risk of local-anesthetic systemic toxicity (LAST). Thus, to decrease the risk of LAST, it is important to know the minimum effective volume (MEV) required for an adequate block. We, therefore, aimed to determine the MEV of ropivacaine 0.75% for induction of surgical anesthesia by the method of US-guided popliteal sciatic nerve block via subparaneural injection.Thirty patients underwent a US-guided PSNB with ropivacaine 0.75% at a 20-mL starting volume. Using a step-up/step-down method, we determined injection volumes for consecutive patients from the preceding patient's outcome. When an effective block was achieved within 40 minutes after injection, the next patient's volume was decreased by 2 mL. If the block failed, the next patient's volume was increased by 2 mL. The sensory and motor blockade was graded according to a 4-point scale. The block was considered a success if a combination of anesthesia and paresis (a score of 3 for both the sensory and motor nerves) was achieved within 40 minutes. The primary outcome measure was the MEV resulting in a successful subparaneural block of the sciatic nerve in 50% of patients (MEV50). Additionally, the data were processed with a probit regression analysis to determine the volume required to produce a complete sciatic nerve block in 90% of subjects (ED90).The MEV50 of 0.75% ropivacaine is 6.14 mL (95% confidence interval, 4.33-7.94 mL). The ED90 by probit analysis for a subparaneural injection was 8.9 mL (95% CI, 7.09-21.75 mL).The 6.14-mL MEV50 of ropivacaine 0.75% represents a 71% reduction

  17. Pain during venous cannulation: Double-blind, randomized clinical trial of analgesic effect between topical amethocaine and eutectic mixture of local anesthetic

    PubMed Central

    Yeoh, CN; Lee, CY

    2012-01-01

    Background: Venous cannulation is often a painful procedure for the patient. Eutectic mixture of local anesthetic (EMLA) is the commonest topical analgesic used but suffers from disadvantages such as slow onset and skin blanching, which may interfere with venous cannulation. Amethocaine is a newer topical analgesic which seems to be devoid of such problems. Materials and Methods: This prospective randomized double-blind study compared the analgesic efficacy of EMLA with amethocaine during venous cannulation in adults. Eighty ASA I-II patients, aged 18–65 years, were recruited. The test drug was applied on the designated site of venous cannulation and covered with an occlusive dressing for at least 60 min prior to the procedure. Data collected included visual analogue score (VAS) during first attempt at venous cannulation, the ease and success rate at cannulation, and cutaneous changes at the application site. Results: Mean and median VAS for the EMLA group were 27.9 ± 9.8 and 30 mm, respectively; while for the Amethocaine group were 19.1 ± 14.1 and 20 mm, respectively. Differences in VAS did not reach statistical significance. No statistically significant differences were observed in the ease and success rate at cannulation. Cutaneous changes in the form of local induration and erythema (three patients in the Amethocaine group) and blanching (eight patients in the EMLA group) were mild, localized, and required no further treatment. No patient developed severe allergic reactions. Conclusion: Topical EMLA and amethocaine were comparable in terms of analgesic efficacy and ease of venous cannulation in adult patients. PMID:22557744

  18. Novel serine-based gemini surfactants as chemical permeation enhancers of local anesthetics: A comprehensive study on structure-activity relationships, molecular dynamics and dermal delivery.

    PubMed

    Teixeira, Raquel S; Cova, Tânia F G G; Silva, Sérgio M C; Oliveira, Rita; do Vale, M Luísa C; Marques, Eduardo F; Pais, Alberto A C C; Veiga, Francisco J B

    2015-06-01

    This work aims at studying the efficacy of a series of novel biocompatible, serine-based surfactants as chemical permeation enhancers for two different local anesthetics, tetracaine and ropivacaine, combining an experimental and computational approach. The surfactants consist of gemini molecules structurally related, but with variations in headgroup charge (nonionic vs. cationic) and in the hydrocarbon chain lengths (main and spacer chains). In vitro permeation and molecular dynamics studies combined with cytotoxicity profiles were performed to investigate the permeation of both drugs, probe skin integrity, and rationalize the interactions at molecular level. Results show that these enhancers do not have significant deleterious effects on the skin structure and do not cause relevant changes on cell viability. Permeation across the skin is clearly improved using some of the selected serine-based gemini surfactants, namely the cationic ones with long alkyl chains and shorter spacer. This is noteworthy in the case of ropivacaine hydrochloride, which is not easily administered through the stratum corneum. Molecular dynamics results provide a mechanistic view of the surfactant action on lipid membranes that essentially corroborate the experimental observations. Overall, this study suggests the viability of these serine-based surfactants as suitable and promising delivery agents in pharmaceutical formulations. PMID:25748796

  19. The conformational stability, solvation and the assignments of the experimental infrared, Raman, 1H and 13C NMR spectra of the local anesthetic drug lidocaine

    NASA Astrophysics Data System (ADS)

    Badawi, Hassan M.; Förner, Wolfgang; Ali, Shaikh A.

    2015-05-01

    The structure, vibrational and 1H and 13C NMR spectra of the local anesthetic drug lidocaine were investigated by the B3LYP/6-311G∗∗ calculations. The molecule was predicted to have the non-planar cis (NCCN ∼ 0°) structures being about 2-6 kcal/mol lower in energy than the corresponding trans (NCCN ∼ 180°) forms. The calculated NCCN (9.6°) and CNCC (-132.2°) torsional angles were in a good qualitative agreement with the reported X-ray angles (3.1 and 13.0°, -102.67 and -77.9°, respectively, for H-bonded dimers). The Gibbs energy of solution of lidocaine in formamide, water, dimethylsulfoxide, acetonitrile, methanol, ethanol and chloroform solutions was estimated at the B3LYP level. The predicted affinity of lidocaine toward the alcohols, acetonitrile and chloroform solutions was in excellent agreement with the reported experimental solubility of the drug in organic solvents. The analysis of the observed vibrational spectra is consistent with the presence of lidocaine in only one conformation at room temperature. The 1H and 13C NMR spectra of lidocaine were interpreted by experimental and DFT calculated chemical shifts of the drug. The RMSD between experimental and theoretical 1H and 13C chemical shifts for lidocaine is 0.47 and 8.26 ppm, respectively.

  20. Auditory cortical and hippocampal local-field potentials to frequency deviant tones in urethane-anesthetized rats: An unexpected role of the sound frequencies themselves.

    PubMed

    Ruusuvirta, Timo; Lipponen, Arto; Pellinen, Eeva-Kaarina; Penttonen, Markku; Astikainen, Piia

    2015-06-01

    The human brain can automatically detect auditory changes, as indexed by the mismatch negativity of event-related potentials. The mechanisms that underlie this response are poorly understood. We recorded primary auditory cortical and hippocampal (dentate gyrus, CA1) local-field potentials to serial tones in urethane-anesthetized rats. In an oddball condition, a rare (deviant) tone (p=0.11) randomly replaced a repeated (standard) tone. The deviant tone was either lower (2200, 2700, 3200, 3700Hz) or higher (4300, 4800, 5300, 5800Hz) in frequency than the standard tone (4000Hz). In an equiprobability control condition, all nine tones were presented at random (p=0.11). Differential responses to deviant tones relative to the standard tone were found in the auditory cortex and the dentate gyrus but not in CA1. Only in the dentate gyrus, the responses were found to be standard- (i.e., oddball condition-) specific. In the auditory cortex, the sound frequencies themselves sufficed to explain their generation. These findings tentatively suggest dissociation among non-contextual afferent, contextual afferent and auditory change detection processes. Most importantly, they remind us about the importance of strict control of physical sound features in mismatch negativity studies in animals. PMID:25911953

  1. Percolation velocity dependence on local concentration in bidisperse granular flows

    NASA Astrophysics Data System (ADS)

    Jones, Ryan P.; Xiao, Hongyi; Deng, Zhekai; Umbanhowar, Paul B.; Lueptow, Richard M.

    The percolation velocity, up, of granular material in size or density bidisperse mixtures depends on the local concentration, particle size ratio, particle density ratio, and shear rate, γ ˙. Discrete element method computational results were obtained for bounded heap flows with size ratios between 1 and 3 and for density ratios between 1 and 4. The results indicate that small particles percolate downward faster when surrounded by large particles than large particles percolate upward when surrounded by small particles, as was recently observed in shear-box experiments. Likewise, heavy particles percolate downward faster when surrounded by light particles than light particles percolate upward when surrounded by heavy particles. The dependence of up / γ ˙ on local concentration results in larger percolation flux magnitudes at high concentrations of large (or light) particles compared to high concentrations of small (or heavy) particles, while local volumetric flux is conserved. The dependence of up / γ ˙ on local concentration can be incorporated into a continuum model, but the impact on global segregation patterns is usually minimal. Partially funded by Dow Chemical Company and NSF Grant No. CBET-1511450.

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

    PubMed

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

    2009-12-01

    Facial locoregional anesthetics (ALR) with nervous blocks are simple and reliable to perform, need little technical resources with a very low iatrogenic risk. These blocks allow anesthesia without deforming wound banks using the same materials as usual local anesthetic procedures. Three principal nervous blocks, in a straight line along the vertical pupil axis, allow managing - even extensive - facial wounds. Few side effects may occur which can be easily prevented. It is a good alternative to local anesthetic for the treatment of extensive and deep areas which is performed with a lower number of injections and a high rate of success. These techniques are easy to learn and practise. These anesthetic techniques allow a nice treatment of different kinds of facial wounds from simple suture to flaps. PMID:19272691

  3. Exploring the Structure of the Voltage-gated Na+ Channel by an Engineered Drug Access Pathway to the Receptor Site for Local Anesthetics*

    PubMed Central

    Lukacs, Peter; Gawali, Vaibhavkumar S.; Cervenka, Rene; Ke, Song; Koenig, Xaver; Rubi, Lena; Zarrabi, Touran; Hilber, Karlheinz; Stary-Weinzinger, Anna; Todt, Hannes

    2014-01-01

    Despite the availability of several crystal structures of bacterial voltage-gated Na+ channels, the structure of eukaryotic Na+ channels is still undefined. We used predictions from available homology models and crystal structures to modulate an external access pathway for the membrane-impermeant local anesthetic derivative QX-222 into the internal vestibule of the mammalian rNaV1.4 channel. Potassium channel-based homology models predict amino acid Ile-1575 in domain IV segment 6 to be in close proximity to Lys-1237 of the domain III pore-loop selectivity filter. The mutation K1237E has been shown previously to increase the diameter of the selectivity filter. We found that an access pathway for external QX-222 created by mutations of Ile-1575 was abolished by the additional mutation K1237E, supporting the notion of a close spatial relationship between sites 1237 and 1575. Crystal structures of bacterial voltage-gated Na+ channels predict that the side chain of rNaV1.4 Trp-1531 of the domain IV pore-loop projects into the space between domain IV segment 6 and domain III pore-loop and, therefore, should obstruct the putative external access pathway. Indeed, mutations W1531A and W1531G allowed for exceptionally rapid access of QX-222. In addition, W1531G created a second non-selective ion-conducting pore, bypassing the outer vestibule but probably merging into the internal vestibule, allowing for control by the activation gate. These data suggest a strong structural similarity between bacterial and eukaryotic voltage-gated Na+ channels. PMID:24947510

  4. Tetrodotoxin-sensitive α-subunits of voltage-gated sodium channels are relevant for inhibition of cardiac sodium currents by local anesthetics.

    PubMed

    Stoetzer, C; Doll, T; Stueber, T; Herzog, C; Echtermeyer, F; Greulich, F; Rudat, C; Kispert, A; Wegner, F; Leffler, A

    2016-06-01

    The sodium channel α-subunit (Nav) Nav1.5 is regarded as the most prevalent cardiac sodium channel required for generation of action potentials in cardiomyocytes. Accordingly, Nav1.5 seems to be the main target molecule for local anesthetic (LA)-induced cardiotoxicity. However, recent reports demonstrated functional expression of several "neuronal" Nav's in cardiomyocytes being involved in cardiac contractility and rhythmogenesis. In this study, we examined the relevance of neuronal tetrodotoxin (TTX)-sensitive Nav's for inhibition of cardiac sodium channels by the cardiotoxic LAs ropivacaine and bupivacaine. Effects of LAs on recombinant Nav1.2, 1.3, 1.4, and 1.5 expressed in human embryonic kidney cell line 293 (HEK-293) cells, and on sodium currents in murine, cardiomyocytes were investigated by whole-cell patch clamp recordings. Expression analyses were performed by reverse transcription PCR (RT-PCR). Cultured cardiomyocytes from neonatal mice express messenger RNA (mRNA) for Nav1.2, 1.3, 1.5, 1.8, and 1.9 and generate TTX-sensitive sodium currents. Tonic and use-dependent block of sodium currents in cardiomyocytes by ropivacaine and bupivacaine were enhanced by 200 nM TTX. Inhibition of recombinant Nav1.5 channels was similar to that of TTX-resistant currents in cardiomyocytes but stronger as compared to inhibition of total sodium current in cardiomyocytes. Recombinant Nav1.2, 1.3, 1.4, and 1.5 channels displayed significant differences in regard to use-dependent block by ropivacaine. Finally, bupivacaine blocked sodium currents in cardiomyocytes as well as recombinant Nav1.5 currents significantly stronger in comparison to ropivacaine. Our data demonstrate for the first time that cardiac TTX-sensitive sodium channels are relevant for inhibition of cardiac sodium currents by LAs. PMID:27000037

  5. Efficacy of subpleural continuous infusion of local anesthetics after thoracoscopic pulmonary resection for primary lung cancer compared to intravenous patient-controlled analgesia

    PubMed Central

    Jung, Joonho; Haam, Seokjin

    2016-01-01

    Background This study compared the efficacy and side effects of intravenous patient-controlled analgesia (IV-PCA) with those of a subpleural continuous infusion of local anesthetic (ON-Q system) in patients undergoing thoracoscopic pulmonary resection for primary lung cancer. Methods We retrospectively reviewed 66 patients who underwent thoracoscopic pulmonary resection for primary lung cancer from January 2014 to August 2015 (36 in the IV-PCA group and 30 in the ON-Q group). The numeric pain intensity scale (NPIS), additional IV injections for pain control, side effects, and early discontinuation of the pain control device were compared. Results There were no differences in the general characteristics of the two groups. The NPIS scores gradually decreased with time (P<0.001), but the two groups had differences in pattern of NPIS scores (P=0.111). There were no differences in the highest NPIS score during admission (4.75±2.35 vs. 5.27±1.87, P=0.334) or the number of additional IV injections for pain control in the same period (0.72±0.94 for IV-PCA vs. 0.83±0.65 for ON-Q; P=0.575). Side effects such as nausea, dizziness, and drowsiness were significantly more frequent with IV-PCA (36.1% vs. 10.0%, P=0.014), and early discontinuation of the pain control device was more frequent in the IV-PCA group (33.3% vs. 6.7%, P=0.008). Conclusions The ON-Q system was equivalent to the IV-PCA for postoperative pain control after thoracoscopic pulmonary resection for primary lung cancer, and it also had fewer effects and early discontinuations. PMID:27499973

  6. The Effects of Instrumental Touching on Infant Pain Perception and the Effects of Eutectic Mixture of Local Anesthetics (EMLA) on the Reduction of Pain

    PubMed Central

    Kucukoglu, Sibel; Celebioglu, Ayda; Caner, Ibrahim; Ok, Gamze; Maden, Rukiye

    2015-01-01

    Background: Premature infants, who have to spend the first week of their lives in neonatal intensive care units (NICUs), experience pain and stress in numerous cases, and they are exposed to many invasive interventions. The studies have shown that uncontrolled pain experienced during early life has negative and long-term side effects, such as distress, and such experiences negatively affect the development of the central nervous system Objectives: The purpose of the study was to examine the effects of touching on infant pain perception and the effects of eutectic mixture of local anesthetic (EMLA) on the reduction of pain. Patients and Methods: Data for the study were collected between March and August 2012 from the neonatal clinic of a university hospital located in eastern Turkey. The population of the study consisted of premature infants who were undergoing treatment, completed the first month and who were approved for Hepatitis B vaccine. The study consisted of two experimental groups and one control group. Information forms, intervention follow-up forms, and Premature Infant Pain Profile (PIPP) were used to collect the data. EMLA cream was applied on the vastus lateralis muscles of the first experimental group before the vaccination. The second experimental group was vaccinated by imitation (placebo), without a needle tip or medicine. Vaccination was carried out using instrumental touch in this group. A routine vaccination was applied in the control group. Results: Mean pain scores of the group to which EMLA was applied were lower in a statistically significant way (P < 0.05) compared to the pain scores of the other groups. Moreover, it was determined that even though invasive intervention was not applied to the newborns, the touching caused them to feel pain just as in the placebo group (P < 0.005). Conclusions: The results demonstrated that EMLA was an effective method for reducing pain in premature newborns, and the use of instrumental touch for invasive

  7. Adherence to Guidelines for the Management of Local Anesthetic Systemic Toxicity Is Improved by an Electronic Decision Support Tool and Designated ‘Reader’

    PubMed Central

    McEvoy, Matthew D.; Hand, William R.; Stoll, W. David; Furse, Cory M.; Nietert, Paul J.

    2014-01-01

    Background and Objectives A hardcopy or paper cognitive aid has been shown to improve performance during the management of simulated local anesthetic systemic toxicity (LAST) when given to the team leader. However, there remains room for improvement in order to ensure a system that can achieve perfect adherence to the published guidelines for LAST management. Recent research has shown that implementing a checklist via a designated reader may be of benefit. Accordingly, we sought to investigate the effect of an electronic decision support tool (DST) and designated ‘Reader’ role on team performance during an in-situ simulation of LAST. Methods Participants were randomized to Reader+DST (N = 16, rDST) and Control (N = 15, memory alone). The rDST group received the assistance of a dedicated Reader on the response team who was equipped with an electronic DST. The primary outcome measure was adherence to guidelines. Results For overall and critical percent correct scores, the rDST group scored higher than Control (99.3% vs 72.2%, P < 0.0001; 99.5% vs 70%, P < 0.0001, respectively). In the LAST scenario, 0 of 15 (0%) in the control group performed 100% of critical management steps, while 15 of 16 (93.8%) in the rDST group did so (P < 0.0001). Conclusions In a prospective, randomized single-blinded study, a designated Reader with an electronic DST improved adherence to guidelines in the management of an in-situ simulation of LAST. Such tools are promising in the future of medicine, but further research is needed to ensure the best methods for implementing them in the clinical arena. PMID:24956454

  8. 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

  9. Mutations M287L and Q266I in the Glycine Receptor α1 Subunit Change Sensitivity to Volatile Anesthetics in Oocytes and Neurons, but Not the Minimal Alveolar Concentration in Knockin Mice

    PubMed Central

    Borghese, Cecilia M.; Xiong, Wei; Oh, S. Irene; Ho, Angel; Mihic, S. John; Zhang, Li; Lovinger, David M.; Homanics, Gregg E.; Eger, Edmond I; Harris, R. Adron

    2012-01-01

    Background Volatile anesthetics (VAs) alter the function of key central nervous system proteins but it is not clear which, if any, of these targets mediates the immobility produced by VAs in the face of noxious stimulation. A leading candidate is the glycine receptor, a ligand-gated ion channel important for spinal physiology. VAs variously enhance such function, and blockade of spinal GlyRs with strychnine affects the minimal alveolar concentration (an anesthetic EC50) in proportion to the degree of enhancement. Methods We produced single amino acid mutations into the glycine receptorα1 subunit that increased (M287L, third transmembrane region) or decreased (Q266I, second transmembrane region) sensitivity to isoflurane in recombinant receptors, and introduced such receptors into mice. The resulting knockin mice presented impaired glycinergic transmission, but heterozygous animals survived to adulthood, and we determined the effect of isoflurane on glycine-evoked responses of brain stem neurons from the knockin mice, and the minimal alveolar concentration for isoflurane and other VAs in the immature and mature knockin mice. Results Studies of glycine-evoked currents in brain stem neurons from knock-in mice confirmed the changes seen with recombinant receptors. No increases in the minimal alveolar concentration were found in knockin mice, but the minimal alveolar concentration for isoflurane and enflurane (but not halothane) decreased in 2-week-old Q266I mice. This change is opposite to the one expected for a mutation that decreases the sensitivity to volatile anesthetics. Conclusion Taken together, these results indicate that glycine receptors containing the α1 subunit are not likely to be crucial for the action of isoflurane and other VAs. PMID:22885675

  10. Profiling the local carrier concentration across a semiconductor quantum dot

    SciTech Connect

    Walrath, J. C.; Lin, Yen-Hsiang; Huang, S.; Goldman, R. S.

    2015-05-11

    We profile the local carrier concentration, n, across epitaxial InAs/GaAs quantum dots (QDs) consisting of 3D islands on top of a 2D alloy layer. We use scanning thermoelectric microscopy to measure a profile of the temperature gradient-induced voltage, which is converted to a profile of the local Seebeck coefficient, S. The S profile is then converted to a conduction band-edge profile and compared with Poisson-Schrodinger band-edge simulations. Our combined computational-experimental approach suggests a reduced carrier concentration in the QD center in comparison to that of the 2D alloy layer. The relative roles of free carrier trapping and/or dopant expulsion are discussed.

  11. Comment on "Local impermeant anions establish the neuronal chloride concentration".

    PubMed

    Luhmann, Heiko J; Kirischuk, Sergei; Kilb, Werner

    2014-09-01

    Glykys et al. (Reports, 7 February 2014, p. 670) proposed that cytoplasmic impermeant anions and polyanionic extracellular matrix glycoproteins establish the local neuronal intracellular chloride concentration, [Cl(-)]i, and thereby the polarity of γ-aminobutyric acid type A (GABAA) receptor signaling. The experimental procedures and results in this study are insufficient to support these conclusions. Contradictory results previously published by these authors and other laboratories are not referred to. PMID:25190788

  12. 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. PMID:27591464

  13. Localized phosphorus spectroscopy in vivo: Quantitation of metabolite concentrations

    NASA Astrophysics Data System (ADS)

    Wylezinska-Arridge, Marzena Malgorzata

    This project was dedicated to the investigation of the factors that may affect absolute quantitation in localized 31P MRS and if possible to the improvement of the accuracy of both localization and quantification. Three aspects have been looked at: 1) the acquisition /localization technique used; 2) the strategy used for conversion of signal amplitude/peak areas into concentrations; and 3) methods for MRS signal processing and analysis. With respect to the first aspect, image selected in vivo spectroscopy (ISIS) and point resolved spectroscopy (PRESS), were considered. Aspects of ISIS localization, including relaxation effects during inversion and excitation adiabatic pulses, and uniformity of spin excitation across the "in vivo" 31P spectral range, were investigated using simulation. In order to reduce the chemical shift displacement error in ISIS, a new adiabatic pulse for spin inversion, has been designed and experimentally verified. For PRESS, the performance of the selective 90[degrees] and 180[degrees] pulses was investigated experimentally and using simulations. The consequences of nonideal flip angles on T1 measurements based on two PRESS experiments were analyzed. Effects of amplitude and phase modulation of the ATP signal during the PRESS sequence were analyzed using product-operator formalism for an AMX system. A tissue substitute material, with known metabolite concentrations and simulating the 31P spectrum obtained from neonatal brain, has been developed for testing quantitation accuracy. The manufacture, physical properties and chemical stability of a material has been presented. The following calibration protocols have been experimentally verified: use of water as an internal concentration reference (ICR), and use of a standard phantom as an external concentration reference (ECR). A modified ECR protocol using the tissue substitute material as a reference, has been suggested to deal with problems related to off-resonance effects. This protocol has

  14. Anesthetic-induced anaphylaxis.

    PubMed

    Norred, Carol L

    2012-04-01

    The purpose of this course is to update nurse anesthetists about anesthetic-induced anaphylaxis. This course discusses the pathophysiologic process of anaphylaxis with descriptions of the allergic immune response and the mediators and mechanisms of mast cell activation. The preoperative identification of patients at high risk and the assessment of potential anesthetic triggers of a hypersensitivity and/or allergic reaction are prudent strategies to minimize the risk of anaphylaxis. Other practices recommended for clinicians include suggestions for anesthetic management to decrease threat of an allergic response in high-risk patients. Furthermore, the identification of the severity grade of hypersensitivity reactions and the appropriate treatment of perioperative anaphylaxis is discussed. In addition, postoperative and follow-up interventions, including testing for patients who have had an anesthetic-induced hypersensitivity reaction, are considered. PMID:22586882

  15. The active titration method for measuring local hydroxyl radical concentration

    NASA Technical Reports Server (NTRS)

    Sprengnether, Michele; Prinn, Ronald G.

    1994-01-01

    We are developing a method for measuring ambient OH by monitoring its rate of reaction with a chemical species. Our technique involves the local, instantaneous release of a mixture of saturated cyclic hydrocarbons (titrants) and perfluorocarbons (dispersants). These species must not normally be present in ambient air above the part per trillion concentration. We then track the mixture downwind using a real-time portable ECD tracer instrument. We collect air samples in canisters every few minutes for roughly one hour. We then return to the laboratory and analyze our air samples to determine the ratios of the titrant to dispersant concentrations. The trends in these ratios give us the ambient OH concentration from the relation: dlnR/dt = -k(OH). A successful measurement of OH requires that the trends in these ratios be measureable. We must not perturb ambient OH concentrations. The titrant to dispersant ratio must be spatially invariant. Finally, heterogeneous reactions of our titrant and dispersant species must be negligible relative to the titrant reaction with OH. We have conducted laboratory studies of our ability to measure the titrant to dispersant ratios as a function of concentration down to the few part per trillion concentration. We have subsequently used these results in a gaussian puff model to estimate our expected uncertainty in a field measurement of OH. Our results indicate that under a range of atmospheric conditions we expect to be able to measure OH with a sensitivity of 3x10(exp 5) cm(exp -3). In our most optimistic scenarios, we obtain a sensitivity of 1x10(exp 5) cm(exp -3). These sensitivity values reflect our anticipated ability to measure the ratio trends. However, because we are also using a rate constant to obtain our (OH) from this ratio trend, our accuracy cannot be better than that of the rate constant, which we expect to be about 20 percent.

  16. Inhaled Anesthetic Potency in Aged Alzheimer Mice

    PubMed Central

    Bianchi, Shannon L.; Caltagarone, Breanna M.; LaFerla, Frank M.; Eckenhoff, Roderic G.; Kelz, Max B.

    2016-01-01

    BACKGROUND The number of elderly patients with frank or incipient Alzheimer’s disease (AD) requiring surgery is growing as the population ages. General anesthesia may exacerbate symptoms of and the pathology underlying AD, so minimizing anesthetic exposure may be important. This requires knowledge of whether the continuing AD pathogenesis alters anesthetic potency. METHODS We determined the induction potency and emergence time for isoflurane, halothane, and sevoflurane using the minimum alveolar anesthetic concentration for loss of righting reflex as an end point in 12- to 14-mo-old triple transgenic Alzheimer (3xTgAD) mice and wild type C57BL6 controls. 3xTgAD mice model AD by harboring three distinct mutations: the APPSwe, Tau, and PS1 human transgenes, each of which has been associated with familial forms of human AD. RESULTS The 3xTgAD mice exhibited mild resistance (from 8% to 30%) to volatile anesthetics but displayed indistinguishable emergence patterns from all three inhaled anesthetics. CONCLUSIONS These results show that the genetic vulnerabilities and neuropathology associated with AD produce a small but significant decrease in sensitivity to the hypnotic actions of three inhaled anesthetics. Emergence times were not altered. PMID:19820240

  17. Neuroprotective properties of vitamin C on equipotent anesthetic concentrations of desflurane, isoflurane, or sevoflurane in high fat diet fed neonatal mice

    PubMed Central

    Xu, Kai-Xiang; Tao, Jun; Zhang, Nan; Wang, Jian-Zhong

    2015-01-01

    Obesity has been reported to be one of the significant contributors to various chronic disease conditions. Childhood obesity has been on an alarming increase over recent years leading to various health complications. Millions of children undergo surgery each year as a part of medical care on various health grounds. In the present study, influence of vitamin C on the effect of obesity and over-weight under anaesthetic exposure was analysed. Separate groups of neonatal mice (C57BL/6) were fed on high-fat diet to induce obesity. The mice were administered with vitamin C at 30 and 60 mg/kg b.wt post natal day 1 (P1) to P21. P7 mice were exposed to equipotent doses of isoflurane or sevoflurane or desflurane. Neuroapoptosis was assessed by measuring activated caspase-3 and TUNEL assay. Plasma S100β levels were detected by ELISA. The mice were assessed for their general behaviour. Morris water maze test was performed to assess the spatial working memory. Anesthesia exposure caused severe neuroapoptosis and also raised the levels of plasma S100β. Neuroapotosis, working memory and learning impairments observed following anesthetics were comparatively more profound on high fat diet fed mice. Desflurane exposure resulted in higher apoptotic counts, learning and memory deficits than equipotent dose of isoflurane and sevoflurane. Vitamin C supplementation offered significant protection against anesthetic induced neurotoxicity and behavioural alterations. Vitamin C administration resulted in marked reduction in neurotoxicity induced by anesthesia and as well improved learning and memory of both normal and high fat diet fed mice. PMID:26379835

  18. 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.

  19. 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.

  20. Phase behavior and local dynamics of concentrated triblock copolymer micelles

    NASA Astrophysics Data System (ADS)

    Yardimci, H.; Chung, B.; Harden, J. L.; Leheny, R. L.

    2005-12-01

    We report a neutron-scattering study to characterize the ordering and local dynamics of spherical micelles formed by the triblock copolymer polyethylene oxide (PEO) - polypropylene oxide (PPO) - polyethylene oxide (Pluronic) in aqueous solution. The study focuses on two Pluronic species, F68 and F108, that have the same weight fraction of PEO but that differ in chain length by approximately a factor of 2. At sufficiently high concentration, both species undergo a sequence of phase changes with increasing temperature from dissolved chains to micelles with liquidlike order to a cubic crystal phase and finally back to a micelle liquid phase. A comparison of the phase diagrams constructed from small-angle neutron scattering indicates that crystallization is suppressed for shorter chain micelles due to fluctuation effects. The intermediate scattering function I(Q,t)/I(Q,0) determined by neutron spin echo displays a line shape with two distinct relaxations. Comparisons between I(Q,t)/I(Q,0) for fully hydrogenated F68 chains in D2O and for F68 with deuterated PEO blocks reveal that the slower relaxation corresponds to Rouse modes of the PPO segments in the concentrated micelle cores. The faster relaxation is identified with longitudinal diffusive modes in the PEO corona characteristic of a polymer brush.

  1. Immune Modulation by Volatile Anesthetics.

    PubMed

    Stollings, Lindsay M; Jia, Li-Jie; Tang, Pei; Dou, Huanyu; Lu, Binfeng; Xu, Yan

    2016-08-01

    Volatile general anesthetics continue to be an important part of clinical anesthesia worldwide. The impact of volatile anesthetics on the immune system has been investigated at both mechanistic and clinical levels, but previous studies have returned conflicting findings due to varied protocols, experimental environments, and subject species. While many of these studies have focused on the immunosuppressive effects of volatile anesthetics, compelling evidence also exists for immunoactivation. Depending on the clinical conditions, immunosuppression and activation due to volatile anesthetics can be either detrimental or beneficial. This review provides a balanced perspective on the anesthetic modulation of innate and adaptive immune responses as well as indirect effectors of immunity. Potential mechanisms of immunomodulation by volatile anesthetics are also discussed. A clearer understanding of these issues will pave the way for clinical guidelines that better account for the impact of volatile anesthetics on the immune system, with the ultimate goal of improving perioperative management. PMID:27286478

  2. Intrinsic organization of the anesthetized brain.

    PubMed

    Liang, Zhifeng; King, Jean; Zhang, Nanyin

    2012-07-25

    The neural mechanism of unconsciousness has been a major unsolved question in neuroscience despite its vital role in brain states like coma and anesthesia. The existing literature suggests that neural connections, information integration, and conscious states are closely related. Indeed, alterations in several important neural circuitries and networks during unconscious conditions have been reported. However, how the whole-brain network is topologically reorganized to support different patterns of information transfer during unconscious states remains unknown. Here we directly compared whole-brain neural networks in awake and anesthetized states in rodents. Consistent with our previous report, the awake rat brain was organized in a nontrivial manner and conserved fundamental topological properties in a way similar to the human brain. Strikingly, these topological features were well maintained in the anesthetized brain. Local neural networks in the anesthetized brain were reorganized with altered local network properties. The connectional strength between brain regions was also considerably different between the awake and anesthetized conditions. Interestingly, we found that long-distance connections were not preferentially reduced in the anesthetized condition, arguing against the hypothesis that loss of long-distance connections is characteristic to unconsciousness. These findings collectively show that the integrity of the whole-brain network can be conserved between widely dissimilar physiologic states while local neural networks can flexibly adapt to new conditions. They also illustrate that the governing principles of intrinsic brain organization might represent fundamental characteristics of the healthy brain. With the unique spatial and temporal scales of resting-state fMRI, this study has opened a new avenue for understanding the neural mechanism of (un)consciousness. PMID:22836253

  3. Anesthetic Complications and Deaths

    PubMed Central

    Pender, John W.

    1968-01-01

    Anesthesiologists should fully inform patients of the possible complications from anesthesia. For rapport with the patient, with whom they usually have no acquaintance until a day or so before an operative procedure, the anesthesiologist should enlist the help of the internist or surgeon who already has established an atmosphere of trust. The extent of morbidity and minor complications from anesthesia has not been adequately recorded. One out of every 1,000 to 2,000 anesthetized patients dies of complications primarily due to or contributed to by anesthesia. Leading causes of death vary from study to study and from year to year. PMID:5652756

  4. The Anesthetic Management of Transcatheter Aortic Valve Implantation.

    PubMed

    Guarracino, Fabio; Baldassarri, Rubia

    2016-06-01

    An increasing number of patients with a high risk for surgery because of advanced age and associated comorbidities that significantly increase the perioperative risk successfully undergo transcatheter aortic valve implantation (TAVI). TAVI is commonly performed under general or local anesthesia or local anesthesia plus mild sedation to achieve a conscious sedation. The anesthetic regimen generally depends on the patient's clinical profile and the procedural technical characteristics, but the center's experience and internal organization likely play an important role in anesthetic decision making. The large variation in anesthetic management among various centers and countries likely depends on the different composition of the operating team and institutional organization. Therefore, a tight interaction among the various members of the TAVI team, including the cardiac anesthetist, provides the proper anesthetic management using the chosen procedural technique. PMID:26403787

  5. Method of center localization for objects containing concentric arcs

    NASA Astrophysics Data System (ADS)

    Kuznetsova, Elena G.; Shvets, Evgeny A.; Nikolaev, Dmitry P.

    2015-02-01

    This paper proposes a method for automatic center location of objects containing concentric arcs. The method utilizes structure tensor analysis and voting scheme optimized with Fast Hough Transform. Two applications of the proposed method are considered: (i) wheel tracking in video-based system for automatic vehicle classification and (ii) tree growth rings analysis on a tree cross cut image.

  6. Effects of anesthetics on ponto-geniculo-occipital waves from the oculomotor nucleus of the cat.

    PubMed

    Yanagida, H; Ashizawa, N; Wakushima, Y; Yamamura, H

    1975-05-01

    Effects of anesthetics and doxapram on pontogeniculo-occipital (PGO) waves from the oculomotor nucleus were studied in acute experiments in cats paralyzed by gallamine triethiodide. The anesthetic agents studied in the present experiment (thiopental, ketamine, Innovar, nitrous oxide, and halothane) decreased, while doxapram increased, the total number of PGO waves. As the doses of anesthetics increased, PGO waves were abolished, but they returned to control levels or below control levels when the concentrations of anesthetics were decreased. The results indicate that the anesthetics studied inhibit the activity of the central mechanism associated with the oculomotor system. PGO waves may prove a useful index of the level of anesthesia. PMID:1130723

  7. Efficacy of Postoperative Pain Management Using Continuous Local Anesthetic Infusion at the Iliac Crest Bone Graft Site in Patients with Adolescent Idiopathic Scoliosis: A Parallel, Double-Blinded, Randomized Controlled Pilot Trial.

    PubMed

    Samartzis, Dino; Bow, Cora; Cheung, Jason Pui Yin; Sham, Phoebe; Mak, Kin-Cheung; Cheung, Wai-Yuen; Wong, Yat-Wa; Luk, Keith D K; Cheung, Kenneth M C; Lawmin, Jean-Claude

    2016-05-01

    Study Design Randomized controlled trial. Objective Adolescent idiopathic scoliosis (AIS) is a common spinal deformity that affects every population. In severe deformity, surgical intervention is performed. Autogenous iliac crest bone graft (ICBG) harvesting remains a common procedure worldwide for scoliosis surgery. Postoperative pain at the ICBG donor site is a major concern in patients undergoing spine surgery that affects postoperative functional outcome and consumes health care resources. Previous studies have noted a decrease in pain and postoperative analgesic use with the application of continuous infusion of anesthetic at the ICBG site in comparison with placebo. However, there is lack of evidence addressing the efficacy of continuous anesthetic infusion at the ICBG site in young patients and in particular those with spinal deformity, such as AIS. As such, this parallel, double-blinded, randomized controlled trial addressed the pain management efficacy of continuous anesthetic infusion versus saline at the ICBG site in patients with AIS during the immediate postoperative period. Methods Participants were randomized into two groups. Group A (control subjects) received 3 mL per hour of saline locally at the ICBG site, and group B (treatment subjects) received a constant rate of infusion of 3 mL per hour of 0.25% levobupivacaine. Both groups received their postoperative intervention for 47 hours. All subjects and outcome assessors were blinded to the type of intervention. Utilizing the visual analog pain scale, pain was assessed at the primary spine surgical site, ICBG site, and contralateral ICBG site. Overall physical pain was assessed by the McGill Pain Questionnaire. The degree of analgesic use and complications were also evaluated. All outcomes were assessed up until the fourth day of the patients' hospitalization following surgery. Results Twelve subjects were recruited (five in group A; seven in group B). No difference was noted at baseline

  8. Locations of local anesthetic dibucaine in model membranes and the interaction between dibucaine and a Na+ channel inactivation gate peptide as studied by 2H- and 1H-NMR spectroscopies.

    PubMed Central

    Kuroda, Y; Ogawa, M; Nasu, H; Terashima, M; Kasahara, M; Kiyama, Y; Wakita, M; Fujiwara, Y; Fujii, N; Nakagawa, T

    1996-01-01

    To study the molecular mechanisms of local anesthesia, locations of local anesthetic dibucaine in model membranes and the interactions of dibucaine with a Na+ channel inactivation gate peptide have been studied by 2H- and 1H-NMR spectroscopies. The 2H-NMR spectra of dibucaine-d9 and dibucaine-d1, which are deuterated at the butoxy group and at the 3 position in its quinoline ring, respectively, have been observed in multilamellar dispersions of the lipid mixture composed of phosphatidylcholine, phosphatidylserine, and phosphatidylethanolamine. 2H-NMR spectra of deuterated palmitic acids incorporated, as a probe, into the lipid mixture containing cholesterol have also been observed. An order parameter, SCD, for each carbon segment was calculated from the observed quadrupole splittings. Combining these results, we concluded that first, the butoxy group of dibucaine is penetrating between the acyl chains of lipids in the model membranes, and second, the quinoline ring of dibucaine is located at the polar region of lipids but not at the hydrophobic acyl chain moiety. These results mean that dibucaine is situated in a favorable position that permits it to interact with a cluster of hydrophobic amino acids (Ile-Phe-Met) within the intracellular linker between domains III and IV of Na+ channel protein, which functions as an inactivation gate. To confirm whether the dibucaine molecule at the surface region of lipids can really interact with the hydrophobic amino acids, we synthesized a model peptide that includes the hydrophobic amino acids (Ac-GGQDIFMTEEQK-OH, MP-1), the amino acid sequence of which corresponds to the linker part of rat brain type IIA Na+ channel, and the one in which Phe has been substituted by Gln (MP-2), and measured 1H-NMR spectra in both phosphate buffer and phosphatidylserine liposomes. It was found that the quinoline ring of dibucaine can interact with the aromatic ring of Phe by stacking of the rings; moreover, the interaction can be reinforced by

  9. Sub-anesthetic concentrations of (R,S)-ketamine metabolites inhibit acetylcholine-evoked currents in α7 nicotinic acetylcholine receptors

    PubMed Central

    Moaddel, Ruin; Abdrakhmanova, Galia; Kozak, Joanna; Jozwiak, Krzysztof; Toll, Lawrence; Jimenez, Lucita; Rosenberg, Avraham; Tran, Thao; Xiao, Yingxian; Zarate, Carlos A.; Wainer, Irving W.

    2012-01-01

    The effect of the (R,S)-ketamine metabolites (R,S)-norketamine, (R,S)-dehydronorketamine, (2S,6S)-hydroxynorketamine and (2R,6R)- hydroxynorketamine on the activity of α7 and α3β4 neuronal nicotinic acetylcholine receptors was investigated using patch-clamp techniques. The data indicated that (R,S)-dehydronorketamine inhibited acetylcholine-evoked currents in α7-nicotinic acetylcholine receptor, IC50 = 55 ± 6 nM, and that (2S,6S)-hydroxynorketamine, (2R,6R)-hydroxynorketamine and (R,S)-norketamine also inhibited α7-nicotinic acetylcholine receptor function at concentrations ≤1μM, while (R,S)-ketamine was inactive at these concentrations. The inhibitory effect of (R,S)-dehydronorketamine was voltage-independent and the compound did not competitively displace selective α7-nicotinic acetylcholine receptor ligands [125I]-α-bungarotoxin and [3H]-epibatidine indicating that (R,S)-dehydronorketamine is a negative allosteric modulator of the α7-nicotinic acetylcholine receptor. (R,S)-Ketamine and (R,S)-norketamine inhibited (S)-nicotine-induced whole-cell currents in cells expressing α3β4-nicotinic acetylcholine receptor, IC50 3.1 and 9.1μM, respectively, while (R,S)-dehydronorketamine, (2S,6S)-hydroxynorketamine and (2R,6R)-hydroxynorketamine were weak inhibitors, IC50 >100μM. The binding affinities of (R,S)-dehydronorketamine, (2S,6S)-hydroxynorketamine and (2R,6R)-hydroxynorketamine at the NMDA receptor were also determined using rat brain membranes and the selective NMDA receptor antagonist [3H]-MK-801. The calculated Ki values were 38.95 μM for (S)-dehydronorketamine, 21.19 μM for (2S,6S)-hydroxynorketamine and > 100 μM for (2R,6R)-hydroxynorketamine. The results suggest that the inhibitory activity of ketamine metabolites at the α7-nicotinic acetylcholine receptor may contribute to the clinical effect of the drug. PMID:23183107

  10. Selected Antimicrobial Activity of Topical Ophthalmic Anesthetics

    PubMed Central

    Reynolds, Margaret M.; Greenwood-Quaintance, Kerryl E.; Patel, Robin; Pulido, Jose S.

    2016-01-01

    Purpose Endophthalmitis is a rare complication of intravitreal injection (IVI). It is recommended that povidone-iodine be the last agent applied before IVI. Patients have reported povidone-iodine application to be the most bothersome part of IVIs. Topical anesthetics have been demonstrated to have antibacterial effects. This study compared the minimum inhibitory concentration (MIC) of topical anesthetic eye drops (proparacaine 0.5%, tetracaine 0.5%, lidocaine 2.0%) and the antiseptic, 5.0% povidone-iodine, against two organisms causing endophthalmitis after IVI. Methods Minimum inhibitory concentration values of topical anesthetics, povidone-iodine, preservative benzalkonium chloride (0.01%), and saline control were determined using five isolates of each Staphylococcus epidermidis and viridans group Streptococcus species (VGS). A broth microdilution technique was used with serial dilutions. Results Lidocaine (8.53 × 10−5mol/mL) had MICs of 4.27 to 8.53 × 10−5 mol/mL, and tetracaine (1.89 × 10−5 mol/mL) had MICs of 9.45 × 10−6 mol/mL for all isolates. Proparacaine (1.7 × 10−5 mol/mL) had MICs of 1.32 to 5.3 × 10−7 and 4.25 × 10−6 mol/mL for S. epidermidis and VGS, respectively). Benzalkonium chloride (3.52 × 10−7 mol/mL) had MICs of 1.86 × 10−9 to 1.1 × 10−8 and 4.40 × 10−8 mol/mL for S. epidermidis and VGS, respectively. Povidone-iodine (1.37 × 10−4 mol/mL) had MICs of 2.14 to 4.28 × 10−6 and 8.56 × 10−6 mol/mL for S. epidermidis and VGS, respectively. Conclusion Proparacaine was the anesthetic with the lowest MICs, lower than that of povidone-iodine. Benzalkonium chloride had lower MICs than proparacaine. All tested anesthetics and povidone-iodine inhibited growth of S. epidermidis and VGS at commercially available concentrations. Translational Relevance For certain patients, it could be possible to use topical anesthetic after povidone-iodine for comfort without inhibiting and perhaps contributing additional antimicrobial

  11. 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

  12. 40 CFR 52.1164 - Localized high concentrations-carbon monoxide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 4 2014-07-01 2014-07-01 false Localized high concentrations-carbon... Localized high concentrations—carbon monoxide. (a) Not later than October 1, 1975, the Commonwealth shall... quality standards for carbon monoxide. Once such localized areas have been identified, the...

  13. 40 CFR 52.1164 - Localized high concentrations-carbon monoxide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 4 2010-07-01 2010-07-01 false Localized high concentrations-carbon... Localized high concentrations—carbon monoxide. (a) Not later than October 1, 1975, the Commonwealth shall... quality standards for carbon monoxide. Once such localized areas have been identified, the...

  14. 40 CFR 52.1164 - Localized high concentrations-carbon monoxide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 4 2013-07-01 2013-07-01 false Localized high concentrations-carbon... Localized high concentrations—carbon monoxide. (a) Not later than October 1, 1975, the Commonwealth shall... quality standards for carbon monoxide. Once such localized areas have been identified, the...

  15. 40 CFR 52.1164 - Localized high concentrations-carbon monoxide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 4 2012-07-01 2012-07-01 false Localized high concentrations-carbon... Localized high concentrations—carbon monoxide. (a) Not later than October 1, 1975, the Commonwealth shall... quality standards for carbon monoxide. Once such localized areas have been identified, the...

  16. 40 CFR 52.1164 - Localized high concentrations-carbon monoxide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 4 2011-07-01 2011-07-01 false Localized high concentrations-carbon... Localized high concentrations—carbon monoxide. (a) Not later than October 1, 1975, the Commonwealth shall... quality standards for carbon monoxide. Once such localized areas have been identified, the...

  17. The effectiveness of diclofenac gel and eutectic mixture of local anesthetic cream on vein puncture pain severity with vein catheter in patient undergoing cesarean section: A randomized, double-blind, placebo-controlled trial

    PubMed Central

    Khalili, Sediqeh; Safavi, Mahboubeh; Rezaei, Rozita; Bidmeshki, Maria; Shirzad, Fatemeh; Nasiri, Mostafa

    2014-01-01

    Aim: This study was aimed to explore the effect of applying diclofenac gel and a eutectic mixture of local anesthetic (EMLA) cream on vein puncture pain severity with vein catheter in the patients undergoing cesarean section. Materials and Methods: The sample comprised 90 women undergoing elective cesarean section that referred to Imam Ali Hospital's maternity section in Amol city (Northern Iran). Data collection tools included visual analog scale for pain severity and a checklist for short term possible side-effects of diclofenac gel, EMLA cream and Vaseline ointment as placebo. Results: The pain of vein puncture with diclofenac gel and EMLA cream was significantly lower than that with the Vaseline ointment (P = 0.001). Similarly, there was a significant difference between using diclofenac gel and EMLA cream in catheter insertion pain severity (P = 0.006). In addition, there was no short term possible side-effect with using diclofenac gel and Vaseline ointment, but a short term side-effect (blanching) was detected in 20% of subjects with EMLA cream. Conclusion: Compared to Vaseline cream, EMLA cream and diclofenac gel application significantly reduces the pain severity associated with vein catheter insertion. Use of diclofenac gel is preferred compared with EMLA cream, because of economics, more efficiency purpose, and no side-effects. PMID:25298943

  18. 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.

  19. 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...

  20. 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...

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. 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...

  7. 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...

  8. 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...

  9. 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. PMID:24061599

  10. Intraoperative awareness risk, anesthetic sensitivity, and anesthetic management for patients with natural red hair: a matched cohort study

    PubMed Central

    Gradwohl, Stephen C.; Aranake, Amrita; Abdallah, Arbi Ben; McNair, Paul; Lin, Nan; Fritz, Bradley A.; Villafranca, Alex; Glick, David; Jacobsohn, Eric; Mashour, George A.

    2015-01-01

    Purpose The red-hair phenotype, which is often produced by mutations in the melanocortin-1 receptor gene, has been associated with an increase in sedative, anesthetic, and analgesic requirements in both animal and human studies. Nevertheless, the clinical implications of this phenomenon in red-haired patients undergoing surgery are currently unknown. Methods In a secondary analysis of a prospective trial of intraoperative awareness, red-haired patients were identified and matched with five control patients, and the relative risk for intraoperative awareness was determined. Overall anesthetic management between groups was compared using Hotelling’s T2 statistic. Inhaled anesthetic requirements were compared between cohorts by evaluating the relationship between end-tidal anesthetic concentration and the bispectral index with a linear mixed-effects model. Time to recovery was compared using Kaplan-Meier analysis, and differences in postoperative pain and nausea/vomiting were evaluated with Chi square tests. Results A cohort of 319 red-haired patients was matched with 1,595 control patients for a sample size of 1,914. There were no significant differences in the relative risk of intraoperative awareness (relative risk = 1.67; 95% confidence interval 0.34 to 8.22), anesthetic management, recovery times, or postoperative pain between red-haired patients and control patients. The relationship between pharmacokinetically stable volatile anesthetic concentrations and bispectral index values differed significantly between red-haired patients and controls (P < 0.001), but without clinical implications. Conclusion There were no demonstrable differences between red-haired patients and controls in response to anesthetic and analgesic agents or in recovery parameters. These findings suggest that perioperative anesthetic and analgesic management should not be altered based on self-reported red-hair phenotype. PMID:25681040

  11. Dynamic characteristics of the cutaneous vasodilator response to a local external pressure application detected by the laser Doppler flowmetry technique on anesthetized rats

    NASA Astrophysics Data System (ADS)

    Humeau, Anne; Koitka, Audrey; Saumet, Jean-Louis; L'Huillier, Jean-Pierre

    2003-10-01

    The laser Doppler flowmetry technique has recently been used to report a significant transient increase of the cutaneous blood flow signal when a local non-noxious pressure is applied progressively on the skin (11.1 Pa/s). The present work analyses the dynamic characteristics of this vasodilatory reflex response on anaesthetised rats. A de-noising algorithm using wavelets is proposed to obtain accurate values of these dynamic characteristics. The blood flow peak and the time to reach this peak are computed on the de-noised recordings. The results show that the mean time to reach the peak of perfusion is 85.3 s (time t = 0 at the beginning of the pressure application). The mean peak value is 188.3 arbitrary units (a.u.), whereas the mean value of the perfusion before the pressure application is 113.4 a.u. The mean minimum value obtained at the end of the experiment is 60.7 a.u. This latter value is, on the average, reached 841.3 s after the beginning of the pressure application. The comparison of the dynamic characteristics, computed with the de-noising algorithm on signals obtained in other situations, will give a better understanding on some cutaneous lesions such as those present on diabetic people.

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

    PubMed

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

    2014-01-01

    Earthworms play an important role in biomedical research, and some surgical procedures require anesthesia. Anesthetic treatments used so far usually induce convulsive body movements connected with extrusion of coelomocyte-containing coelomic fluid that may affect experimental results. Extensive movements connected with the expulsion of coelomic fluid are exploited by immunologists as a method of harvesting immunocompetent coelomocytes from worms subjected to mild electrostimulation (4.5V). The aim of the investigations was to find anesthetic drugs without unintentional coelomocyte depletion. Experiments were performed on adult specimens of Dendrobaena veneta, the coelomocytes of which consist of amoebocytes and riboflavin-storing eleocytes. Earthworm mobility was filmed and extrusion of coelomocytes was quantified by detection of eleocyte-derived riboflavin in immersion fluid. Treatments included earthworms (1) immersed either in physiological saline (controls) or in a solution of one of the tested anesthetic drugs; (2) electrostimulated immediately after anesthesia, and (3) electrostimulated a second time after a 1-hour recovery period. The well-established fish and amphibian anesthetic agent MS-222 induced coelomocyte expulsion. In contrast, solutions of the mammalian local anesthetic drug, prilocaine hydrochloride (0.25-0.5%, 5-10 min) caused temporal earthworm immobilization followed by recovery, thus showing utility as an efficient earthworm anesthetic. PMID:25134346

  13. A simple and high-resolution HPLC-PDA method for simultaneous quantification of local anesthetics in in vitro buccal permeation enhancement studies.

    PubMed

    Couto, Renê O; Cubayachi, Camila; Lopez, Renata F V; de Gaitani, Cristiane M; Pedrazzi, Vinícius; de Freitas, Osvaldo

    2016-06-01

    A simple, isocratic, high-resolution and prompt HPLC-PDA method was developed and validated for the simultaneous quantification of prilocaine (PCL) and lidocaine (LCL) hydrochlorides in in vitro buccal iontophoresis-driven permeation studies. A reversed-phase C18 column (250 mm x 4.6 mm, 3μm, 110Å) was used for the chromatographic separation. The mobile phase contained acetonitrile: 0.1M sodium phosphate buffer, pH 7.0 (1:1, v/v), plus 0.05% (v/v) diethylamine. The isocratic flow rate was set at 1 mL/min and the detection wavelength was 203 nm. PCL and LCL eluted in 8.9 min and 13 min, respectively, and the system suitability parameters varied within an acceptable range. The method was selective, sensitive, precise, accurate and robust, producing a linear plot at the concentration range of 0.25 to 10 µg/mL. The application of this method was demonstrated by a significant enhancement of the permeation of PCL and LCL with the application of iontophoresis (1 mA/cm(2) per 1 h) through isolated porcine esophageal epithelium. The amount of the drug retained in the epithelium also increased with the application of an electrical current. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26379211

  14. Influence of local anesthetics with or without epinephrine 1/80000 on blood pressure and heart rate: A randomized double-blind experimental clinical trial

    PubMed Central

    Ketabi, Mohammad; Shamami, Mehrnaz Sadighi; Alaie, Maryam; Shamami, Mehrnoosh Sadighi

    2012-01-01

    Background: Local anesthesia (LA) with epinephrine have an important role in pain and bleeding control. However, most clinicians believe LA + epinephrine may cause rapid raise in blood pressure (BP) and heart rate (HR). The aim of this research was to compare the changes in HR and BP after administration of lidocaine with and without epinephrine 1/80000 in two infiltration (INF) and inferior alveolar nerve block methods (IANB). Materials and Methods: The study was a randomized double-blind experimental clinical trial. Forty subjects were divided into two equal groups and two subgroups. In one group, INF and in the other group, IANB were used and, further, in one subgroup lidocaine and in another subgroup, lidocaine plus epinephrine were used. BP and HR were recorded before and 10 min after. The paired t-test for intragroup differences and independent t-test for intergroup analysis were used at the significant level of P≤0.05. Results: The mean BP and HR values were reduced after injection of lidocaine in both INF and IANB compared with baseline. The differences were statistically significant (P < 0.05), but, on comparing these values between the two injection methods, the differences were not statically significant (P = 0.089 and 0.066, respectively). The mean BP and HR values were increased after injection of lidocaine plus epinephrine in both INF and IANB compared with baseline, and these were statistically significant (P < 0.05) but, on comparing these values between the two methods, the differences were not statically significant (P = 0.071 and 0.092, respectively). Conclusion: The rise in BP and HR following injection of lidocaine plus epinephrine was statistically significant compared with baseline in both INF and IANB, but this was not clinically and numerically considerable. PMID:23162585

  15. 63,65Cu NMR Method in a Local Field for Investigation of Copper Ore Concentrates

    NASA Astrophysics Data System (ADS)

    Gavrilenko, A. N.; Starykh, R. V.; Khabibullin, I. Kh.; Matukhin, V. L.

    2015-01-01

    To choose the most efficient method and ore beneficiation flow diagram, it is important to know physical and chemical properties of ore concentrates. The feasibility of application of the 63,65Cu nuclear magnetic resonance (NMR) method in a local field aimed at studying the properties of copper ore concentrates in the copper-iron-sulfur system is demonstrated. 63,65Cu NMR spectrum is measured in a local field for a copper concentrate sample and relaxation parameters (times T1 and T2) are obtained. The spectrum obtained was used to identify a mineral (chalcopyrite) contained in the concentrate. Based on the experimental data, comparative characteristics of natural chalcopyrite and beneficiated copper concentrate are given. The feasibility of application of the NMR method in a local field to explore mineral deposits is analyzed.

  16. Quantification of brain glycogen concentration and turnover through localized 13C NMR of both the C1 and C6 resonances.

    PubMed

    van Heeswijk, Ruud B; Morgenthaler, Florence D; Xin, Lijing; Gruetter, Rolf

    2010-04-01

    We have recently shown that at isotopic steady state (13)C NMR can provide a direct measurement of glycogen concentration changes, but that the turnover of glycogen was not accessible with this protocol. The aim of the present study was to design, implement and apply a novel dual-tracer infusion protocol to simultaneously measure glycogen concentration and turnover. After reaching isotopic steady state for glycogen C1 using [1-(13)C] glucose administration, [1,6-(13)C(2)] glucose was infused such that isotopic steady state was maintained at the C1 position, but the C6 position reflected (13)C label incorporation. To overcome the large chemical shift displacement error between the C1 and C6 resonances of glycogen, we implemented 2D gradient based localization using the Fourier series window approach, in conjunction with time-domain analysis of the resulting FIDs using jMRUI. The glycogen concentration of 5.1 +/- 1.6 mM measured from the C1 position was in excellent agreement with concomitant biochemical determinations. Glycogen turnover measured from the rate of label incorporation into the C6 position of glycogen in the alpha-chloralose anesthetized rat was 0.7 micromol/g/h. PMID:20186693

  17. Sevoflurane-enriched blood cardioplegia: the intramyocardial delivery of a volatile anesthetic.

    PubMed

    van der Baan, A; Kortekaas, K A; van Es, E; Meier, S; Klautz, R J M; Engbers, F H M

    2015-05-01

    Myocardial ischemia/reperfusion injury is a major problem in cardiac surgery, characterized by an enhanced inflammatory response postoperatively. Sevoflurane has anti-inflammatory effects and may attenuate this injury. This study describes a novel approach to using sevoflurane as a local anti-inflammatory drug and not as an anesthetic. Therefore, a pediatric oxygenator with a sevoflurane vaporizer was integrated into the blood cardioplegia system of an adult bypass system. In addition, a gas blender was implemented to regulate pO2 and pCO2 concentrations in the cardioplegia. This proof-of-principle study was tested in vivo and shows that it is feasible to deliver sevoflurane locally while regulating O2 and CO2 concentrations. Moreover, this set-up enables one to use only the specific cardioprotective features of sevoflurane. Inflammatory responses were attenuated, both locally (i.e. the heart) as well as systemically through intramyocardial delivery of sevoflurane. PMID:25085855

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

    PubMed

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

    2016-01-01

    General anesthetics are commonly used in animal models to study how sensory signals are represented in the brain. Here, we used two-photon (2P) calcium activity imaging with cellular resolution to investigate how neuronal activity in layer 2/3 of the mouse barrel cortex is modified under the influence of different concentrations of chemically distinct general anesthetics. Our results show that a high isoflurane dose induces synchrony in local neuronal networks and these cortical activity patterns closely resemble those observed in EEG recordings under deep anesthesia. Moreover, ketamine and urethane also induced similar activity patterns. While investigating the effects of deep isoflurane anesthesia on whisker and auditory evoked responses in the barrel cortex, we found that dedicated spatial regions for sensory signal processing become disrupted. We propose that our isoflurane-2P imaging paradigm can serve as an attractive model system to dissect cellular and molecular mechanisms that induce the anesthetic state, and it might also provide important insight into sleep-like brain states and consciousness. PMID:27147963

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

    PubMed Central

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

    2016-01-01

    General anesthetics are commonly used in animal models to study how sensory signals are represented in the brain. Here, we used two-photon (2P) calcium activity imaging with cellular resolution to investigate how neuronal activity in layer 2/3 of the mouse barrel cortex is modified under the influence of different concentrations of chemically distinct general anesthetics. Our results show that a high isoflurane dose induces synchrony in local neuronal networks and these cortical activity patterns closely resemble those observed in EEG recordings under deep anesthesia. Moreover, ketamine and urethane also induced similar activity patterns. While investigating the effects of deep isoflurane anesthesia on whisker and auditory evoked responses in the barrel cortex, we found that dedicated spatial regions for sensory signal processing become disrupted. We propose that our isoflurane-2P imaging paradigm can serve as an attractive model system to dissect cellular and molecular mechanisms that induce the anesthetic state, and it might also provide important insight into sleep-like brain states and consciousness. PMID:27147963

  20. Clinical comparison of preinjection anesthetics.

    PubMed

    Plotkin, S

    1998-02-01

    To minimize injection anxiety and discomfort, the podiatric surgeon can choose from a variety of topical anesthetics. Available modalities include skin refrigerants (also referred to as vapocoolants), needleless injection systems, iontophoresis, and eutectic mixtures of topical anesthetic cream such as EMLA Cream. Many of the vapocoolants contain chlorofluorocarbons, which are known to damage the ozone layer, a stratospheric layer that filters out harmful ultraviolet B radiation. In accordance with the 1992 Montreal Protocol, which banned the manufacture of certain chlorofluorocarbon compounds, many commonly used vapocoolants will no longer be available. Some newly marketed vapocoolants produce extremely cold temperatures, limiting their use. This article discusses the properties of various vapocoolants and other topical anesthetics and compares their effectiveness in patient trials. PMID:9503770

  1. [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. PMID:27359239

  2. The influence of the local oxygen vacancy concentration on the piezoresponse of strontium titanate thin films.

    PubMed

    Andrä, Michael; Gunkel, Felix; Bäumer, Christoph; Xu, Chencheng; Dittmann, Regina; Waser, Rainer

    2015-09-14

    In this study, the influence of the local oxygen vacancy concentration on piezoresponse force microscopy (PFM) measurements was investigated. Ultra-thin single-crystalline SrTiO3 thin films were deposited on niobium doped SrTiO3 substrates and analyzed using a combined PFM and local conductive atomic force microscopy (LC-AFM) measurement setup. After applying different polarization voltages between ±2 V and ±5 V to the thin films, we simultaneously observed an anomalous contrast in the piezoresponse amplitude and phase signal as well as a changed local conductivity in the exact same region. Since classic ferroelectricity can be excluded as the reason for the observed contrast, an influence of the local oxygen vacancy concentration on the piezoresponse is considered. Additionally, the surface potential was measured using Kelvin probe force microscopy (KPFM) revealing a change in surface potential in the regions of the applied voltage. The observed relaxation of the surface potential over time was fitted to a local oxidation reaction of the previously reduced regions of the ultra-thin SrTiO3 film. We propose a model that relates the local oxygen vacancy concentration to the surface potential. The influence of the oxygen vacancy concentration on the PFM measurements is explained. PMID:26246071

  3. Environmental implications of anesthetic gases.

    PubMed

    Yasny, Jeffrey S; White, Jennifer

    2012-01-01

    For several decades, anesthetic gases have greatly enhanced the comfort and outcome for patients during surgery. The benefits of these agents have heavily outweighed the risks. In recent years, the attention towards their overall contribution to global climate change and the environment has increased. Anesthesia providers have a responsibility to minimize unnecessary atmospheric pollution by utilizing techniques that can lessen any adverse effects of these gases on the environment. Moreover, health care facilities that use anesthetic gases are accountable for ensuring that all anesthesia equipment, including the scavenging system, is effective and routinely maintained. Implementing preventive practices and simple strategies can promote the safest and most healthy environment. PMID:23241038

  4. Quantifying local traffic contributions to NO2 and NH3 concentrations in natural habitats.

    PubMed

    Gadsdon, Sally R; Power, Sally A

    2009-10-01

    NO(2) and NH(3) concentrations were measured across a Special Area for Conservation in southern England, at varying distances from the local road network. Exceedances of the critical levels for these pollutants were recorded at nearly all roadside locations, extending up to 20 m away from roads at some sites. Further, paired measurements of NH(3) and NO(2) concentrations revealed differences between ground and tree canopy levels. At "background" sites, away from the direct influence of roads, concentrations were higher within tree canopies than at ground level; the reverse pattern was, however, seen at roadside locations. Calculations of pollutant deposition rates showed that nitrogen inputs are dominated by NH(3) at roadside sites. This study demonstrates that local traffic emissions contribute substantially to the exceedance of critical levels and critical loads, and suggests that on-site monitoring is needed for sites of nature conservation value which are in close proximity to local transport routes. PMID:19427723

  5. Effects of Anesthetic Management on Early Postoperative Recovery, Hemodynamics and Pain After Supratentorial Craniotomy

    PubMed Central

    Ayrian, Eugenia; Kaye, Alan David; Varner, Chelsia L.; Guerra, Carolina; Vadivelu, Nalini; Urman, Richard D.; Zelman, Vladimir; Lumb, Philip D.; Rosa, Giovanni; Bilotta, Federico

    2015-01-01

    Various clinical trials have assessed how intraoperative anesthetics can affect early recovery, hemodynamics and nociception after supratentorial craniotomy. Whether or not the difference in recovery pattern differs in a meaningful way with anesthetic choice is controversial. This review examines and compares different anesthetics with respect to wake-up time, hemodynamics, respiration, cognitive recovery, pain, nausea and vomiting, and shivering. When comparing inhalational anesthetics to intravenous anesthetics, either regimen produces similar recovery results. Newer shorter acting agents accelerate the process of emergence and extubation. A balanced inhalational/intravenous anesthetic could be desirable for patients with normal intracranial pressure, while total intravenous anesthesia could be beneficial for patients with elevated intracranial pressure. Comparison of inhalational anesthetics shows all appropriate for rapid emergence, decreasing time to extubation, and cognitive recovery. Comparison of opioids demonstrates similar awakening and extubation time if the infusion of longer acting opioids was ended at the appropriate time. Administration of local anesthetics into the skin, and addition of corticosteroids, NSAIDs, COX-2 inhibitors, and PCA therapy postoperatively provided superior analgesia. It is also important to emphasize the possibility of long-term effects of anesthetics on cognitive function. More research is warranted to develop best practices strategies for the future that are evidence-based. PMID:26345202

  6. General Anesthetic Actions on GABAA Receptors

    PubMed Central

    Garcia, Paul S; Kolesky, Scott E; Jenkins, Andrew

    2010-01-01

    General anesthetic drugs interact with many receptors in the nervous system, but only a handful of these interactions are critical for producing anesthesia. Over the last 20 years, neuropharmacologists have revealed that one of the most important target sites for general anesthetics is the GABAA receptor. In this review we will discuss what is known about anesthetic – GABAA receptor interactions. PMID:20808541

  7. Anesthetic Management of a Patient With Takayasu Arteritis.

    PubMed

    Yoshida, Mitsuhiro; Yamamoto, Toru; Shiiba, Shunji; Harano, Nozomu; Sago, Teppei; Nunomaki, Masahito; Watanabe, Seiji

    2016-01-01

    Takayasu arteritis is a rare chronic progressive panendarteritis involving the aorta and its main branches. Anesthesia in patients with this disease can be complicated by severe uncontrolled hypertension, end-organ dysfunction, and stenosis of major blood vessels. In this case, general anesthesia was induced with sevoflurane and remifentanil without complications. To prevent intraoperative complications, we conducted intubation with a rigid video laryngoscope with careful consideration of the concentrations of analgesics and sedatives used. This case demonstrates the importance of anesthetic techniques for maintaining adequate tissue perfusion without hemodynamic changes in the anesthetic management of patients with Takayasu arteritis. PMID:26866409

  8. Neuronal nicotinic acetylcholine receptor modulation by general anesthetics.

    PubMed

    Flood, P; Role, L W

    1998-11-23

    1. General anesthetics have been shown to inhibit synaptic transmission in multiple areas of the central and peripheral nervous systems. 2. The mechanism of inhibition is not well understood. 3. It has become clear that general anesthetics modulate the function of members of the ligand gated ion channel superfamily, including receptors for GABA(A), glycine (Harrison et al., Mol. Pharmacol. 44(3), 1993, 628-632) and 5HT3 (Zhou and Lovinger, J. Pharmacol. Exp. Therap. 278(2), 1996, 732-740). 4. Studies of the activity of general anesthetics on recombinant neuronal nicotinic acetylcholine receptors have added this receptor family to those potently inhibited by general anesthetics (Flood et al., Anesthesiology 86(4), 1997, 859-865; Violet et al., Anesthesiology 86(4), 1997, 866-874). 5. Studies of neuronal nicotinic receptors in native neurons suggest that the inhibition of these receptors by general anesthetics at low clinical concentrations may be biologically significant (Nicoll, Science 199(4327), 1978, 451-452). 6. Recent work on neuronal nicotinic acetylcholine receptors in the central nervous system suggests that their primary role may be to modulate synaptic transmission (Role and Berg, Neuron 16(6), 1996, 1077-1085). 7. Thus, inhibition of nicotinic modulation in the central nervous system may result in inhibition of synaptic transmission and some of the behavioral consequences of general anesthesia. PMID:10049135

  9. Anesthetic implications of laparoscopic surgery.

    PubMed Central

    Cunningham, A. J.

    1998-01-01

    Minimally invasive therapy aims to minimize the trauma of any interventional process but still achieve a satisfactory therapeutic result. The development of "critical pathways," rapid mobilization and early feeding have contributed towards the goal of shorter hospital stay. This concept has been extended to include laparoscopic cholecystectomy and hernia repair. Reports have been published confirming the safety of same day discharge for the majority of patients. However, we would caution against overenthusiastic ambulatory laparoscopic cholecystectomy on the rational but unproven assumption that early discharge will lead to occasional delays in diagnosis and management of postoperative complications. Intraoperative complications of laparoscopic surgery are mostly due to traumatic injuries sustained during blind trocar insertion and physiologic changes associated with patient positioning and pneumoperitoneum creation. General anesthesia and controlled ventilation comprise the accepted anesthetic technique to reduce the increase in PaCO2. Investigators have recently documented the cardiorespiratory compromise associated with upper abdominal laparoscopic surgery, and particular emphasis is placed on careful perioperative monitoring of ASA III-IV patients during insufflation. Setting limits on the inflationary pressure is advised in these patients. Anesthesiologists must maintain a high index of suspicion for complications such as gas embolism, extraperitoneal insufflation and surgical emphysema, pneumothorax and pneumomediastinum. Postoperative nausea and vomiting are among the most common and distressing symptoms after laparoscopic surgery. A highly potent and selective 5-HT3 receptor antagonist, ondansetron, has proven to be an effective oral and IV prophylaxis against postoperative emesis in preliminary studies. Opioids remain an important component of the anesthesia technique, although the introduction of newer potent NSAIDs may diminish their use. A preoperative

  10. The Thermodynamics of General and Local Anesthesia

    NASA Astrophysics Data System (ADS)

    Græsbøll, Kaare; Sasse-Middelhoff, Henrike; Heimburg, Thomas

    2014-05-01

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

  11. The Thermodynamics of General and Local Anesthesia

    PubMed Central

    Græsbøll, Kaare; Sasse-Middelhoff, Henrike; Heimburg, Thomas

    2014-01-01

    General anesthetics are known to cause depression of the freezing point of transitions in biomembranes. This is a consequence of ideal mixing of the anesthetic drugs in the membrane fluid phase and exclusion from the solid phase. Such a generic law provides physical justification of the famous Meyer-Overton rule. We show here that general anesthetics, barbiturates, and local anesthetics all display the same effect on melting transitions. Their effect is reversed by hydrostatic pressure. Thus, the thermodynamic behavior of local anesthetics is very similar to that of general anesthetics. We present a detailed thermodynamic analysis of heat capacity profiles of membranes in the presence of anesthetics. Using this analysis, we are able to describe experimentally observed calorimetric profiles and predict the anesthetic features of arbitrary molecules. In addition, we discuss the thermodynamic origin of the cutoff effect of long-chain alcohols and the additivity of the effect of general and local anesthetics. PMID:24853743

  12. The thermodynamics of general and local anesthesia.

    PubMed

    Graesbøll, Kaare; Sasse-Middelhoff, Henrike; Heimburg, Thomas

    2014-05-20

    General anesthetics are known to cause depression of the freezing point of transitions in biomembranes. This is a consequence of ideal mixing of the anesthetic drugs in the membrane fluid phase and exclusion from the solid phase. Such a generic law provides physical justification of the famous Meyer-Overton rule. We show here that general anesthetics, barbiturates, and local anesthetics all display the same effect on melting transitions. Their effect is reversed by hydrostatic pressure. Thus, the thermodynamic behavior of local anesthetics is very similar to that of general anesthetics. We present a detailed thermodynamic analysis of heat capacity profiles of membranes in the presence of anesthetics. Using this analysis, we are able to describe experimentally observed calorimetric profiles and predict the anesthetic features of arbitrary molecules. In addition, we discuss the thermodynamic origin of the cutoff effect of long-chain alcohols and the additivity of the effect of general and local anesthetics. PMID:24853743

  13. Genotoxicity of Anesthetics Evaluated In Vivo (Animals)

    PubMed Central

    Braz, Mariana G.; Karahalil, Bensu

    2015-01-01

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

  14. Profiling the local carrier concentration and dopant distribution across a semiconductor quantum dot

    NASA Astrophysics Data System (ADS)

    Walrath, J. C.; Chang, A. S.; Lin, Y. H.; Huang, S.; Goldman, R. S.

    We profile the local carrier concentration, n, across epitaxial InAs/GaAs quantum dots (QDs) consisting of 3D islands on top of a 2D alloy layer. We use scanning thermoelectric microscopy to profile the temperature gradient-induced voltage, which is converted to a profile of the local Seebeck coefficient, S. The S profile is then converted to a conduction band-edge profile and compared with Poisson-Schrodinger band-edge simulations. Our combined computational-experimental approach suggests a reduced carrier concentration in the QD center in comparison to that of the 2D alloy layer. We further use 3D atom probe tomography, which enables 3D imaging with a few Angstrom resolution, to profile the distribution of Si dopants. We discuss the correlation between the Si dopant distribution and the observed carrier concentration profile.

  15. Anesthetic considerations in orthopedic patients with or without trauma.

    PubMed

    Chohan, Amandeep S

    2010-05-01

    Anesthetic management of orthopedic patients could vary from normal routine management to more challenging critical management depending on the state in which the patient is presented. Multimodal pain management strategies incorporating opioids, which are the mainstay drugs for pain management, along with adjunctive drugs like local anesthetics (eg, lidocaine), dissociative anesthetics (eg, ketamine), and alpha-2 agonists (eg, dexmedetomidine), could improve overall patient comfort and help prevent establishment of chronic pain pathways. Also, use of local nerve blocks can prevent nociception right at the point of origin. Orthopedic patients with multiple organ traumas like head injuries, spinal injuries, pulmonary fat embolism, compartment syndrome, or thoracic injuries are high-risk patients in which any life-threatening organ pathology should be addressed before the patient is put under general anesthesia. Interactions of various drugs like antibiotics and neuromuscular blocking agents used in the perioperative period in orthopedic patients should warrant a careful consideration with respect to their interactions with each other and other anesthetic drugs used. PMID:20515674

  16. Evaluation of serum concentrations of the selected cytokines in patients with localized scleroderma

    PubMed Central

    Budzyńska-Włodarczyk, Jolanta; Michalska-Jakubus, Małgorzata M.; Kowal, Małgorzata

    2016-01-01

    Introduction Localized scleroderma is an autoimmune disease primarily affecting the skin. The cause of disease remains unexplained although environmental factors are implicated, which are likely to be responsible for activation of the endothelium and subsequent inflammation leading to excessive synthesis of collagen and extracellular matrix components. Aim To determine concentrations of interleukin (IL)-27, transforming growth factor (TGF)-β1, TGF-β2, IL-6, and sIL-6R in patients with localized scleroderma compared to controls and to assess the relations between their levels and laboratory markers. Material and methods The study encompassed 17 females with localized scleroderma (aged 25–67). The control group consisted of 30 age-matched healthy women. The blood was sampled from the basilic vein. Serum levels of cytokines were determined using ELISA. Results The TGF-β2 levels were found to be significantly lower in patients with localized scleroderma compared to controls. Concentrations of TGF-β1 were decreased in scleroderma patients when compared to controls but without statistical significance. There were no significant differences in serum IL-6, sIL-6R and IL-27 levels between patients and the control group; however, we found a significant positive correlation between the level of sIL-6 and ESR among subjects with localized scleroderma. Conclusions The findings of decreased serum levels of TGF-β1 and TGF-β2 in patients with localized scleroderma demonstrate a possible association of these cytokines with pathogenesis of the disease. The results suggest also that sIL-6R is likely to be involved in inflammation in patients with localized scleroderma. PMID:26985179

  17. Localization of GFP-tagged concentrative nucleoside transporters in a renal polarized epithelial cell line.

    PubMed

    Mangravite, L M; Lipschutz, J H; Mostov, K E; Giacomini, K M

    2001-05-01

    Many nucleosides undergo active reabsorption within the kidney, probably via nucleoside transporters. To date, two concentrative nucleoside transporters have been cloned, the sodium-dependent purine-selective nucleoside transporter (SPNT) and concentrative nucleoside transporter 1 (CNT1). We report the stable expression of green fluorescence protein (GFP)-tagged SPNT and CNT1 in Madin-Darby canine kidney (MDCK) cells, a polarized renal epithelial line. We demonstrate that the GFP tag does not alter the substrate selectivity and only modestly affects the kinetic activity of the transporters. By using confocal microscopy and functional studies, both SPNT and CNT1 are localized primarily to the apical membrane of MDCK and LLC-PK(1) cells. Apical localization of these transporters suggests a role in renal nucleoside reabsorption and regulation of tubular function via the adenosine pathway. PMID:11292631

  18. Local fish consumption and serum PCB concentrations among Mohawk men at Akwesasne

    SciTech Connect

    Fitzgerald, E.F.; Deres, D.A.; Hwang, S.A.; Bush, B.; Yang, B.; Tarbell, A.; Jacobs, A.

    1999-02-01

    A study was conducted to assess local fish consumption patterns and their relationship to concentrations of total polychlorinated biphenyls (PCBs) in the serum of Mohawk men residing near three hazardous waste sites. From 1992 to 1995, 139 men were interviewed and donated a 20-ml venous blood sample. The results indicated that the men ate a mean of 21.2 local fish meals during the past year, compared with annual means of 27.7 meals 1--2 years before and 88.6 meals more than 2 years before. This change is probably a consequence of advisories issued against the consumption of local fish, since 97% of the mean were aware of the advisories and two-third had changed their behavior as a result. Multiple regression analysis revealed that serum PCB levels increased with age and local fish consumption. The data suggest that local fish consumption has contributed to body burdens in this population and that the advisories have been effective in modifying local fish consumption habits.

  19. Comparison of the concentration-effect relationship of a local antiinflammatory agent and oral acetylsalicylic acid: the value of local application.

    PubMed

    Poisson, M; Ralambosoa, C; Blehaut, H; Astoin, J

    1985-01-01

    Using a pharmacological model, the comparison between acetylsalicylic acid (ASA), administered orally, and a solution combining two salicylate derivatives (ethyl 5-methoxy-salicylate and 3-phenyl-propyl-salicylate), applied locally, demonstrated the value of the local application. Indeed, the pharmacological activity was highly significant and directly related to the tissue concentration of salicyl ions, which was higher after local application of the solution than after oral administration of ASA. The local solution also resulted in a lower plasma concentration of salicylate ions, allowing high plasma salicylate concentrations to be avoided. PMID:4074414

  20. Somatostatin Analogs and Tumor Localization Do Not Influence Vitamin D Concentration in Patients with Neuroendocrine Tumors.

    PubMed

    Motylewska, Ewelina; Gawronska, Joanna; Niedziela, Agata; Melen-Mucha, Gabriela; Lawnicka, Hanna; Komorowski, Jan; Swietoslawski, Jacek; Stepien, Henryk

    2016-04-01

    Patients with neuroendocrine tumors (NETs), malignancies of rare but still rising incidence, may be a group at higher risk of vitamin D insufficiency. The gastrointestinal tumor prevalence and somatostatin analog (SSA) therapy may cause vitamin D malabsorption. The aim of this study was to evaluate the serum level of vitamin D in NET patients. A total of 36 NET patients were enrolled into the experimental group and 16 individuals were enrolled into the control group. All patients were further classified into subgroups according to primary tumor localization (gastropancreatic, lung, and other NETs) or therapy (with or without SSA treatment). The concentrations of total 25(OH)D were assayed with Electrochemiluminescence immunoassay (ECLIA). Serum concentration of 25(OH)D in NET patients did not differ significantly from that of the control group. However, the average level of 25(OH)D in both groups met the criteria of vitamin D deficiency. Importantly, SSA therapy did not aggravate vitamin D deficiency. Moreover, the concentration of 25(OH)D in the studied group was not significantly influenced by primary tumor localization, patient age, or season. Vitamin D deficiency is a widespread disorder affecting both NET patients and individuals without other health problems, and SSA and gastrointestinal tumor localization do not exacerbate this condition. PMID:27028957

  1. Objective Circulation type classifications for the estimation of local PM10 concentrations in Bavarian cities (Germany)

    NASA Astrophysics Data System (ADS)

    Weitnauer, Claudia; Beck, Christoph; Jacobeit, Jucundus

    2013-04-01

    Concentrations of particulate matter with a particle distribution of a median aerodynamic diameter < 10 μm (PM10), are known to be relevant for public health, notably concerning cardiovascular and respiratory diseases. High pollution events of PM10 are defined by a threshold of a daily mean concentration of 50μg/m³ by directive 1999/30/EC and following directive 2008/50/EC of the European Union, which are relevant for regional air-quality mitigation strategies. Local concentrations of these fine particles are influenced by meteorological parameters on different scales, e.g. local meteorological conditions and large scale circulation dynamics. In order to detect critical periods of high PM10 concentrations, one focus in recent studies is the improvement of accurate short-term deterministic and statistical prediction models as well as reliable approaches for long-term air-quality prediction. The general relationship between local PM10 and large-scale circulation dynamics - as for example reflected by weather- or circulation types - has been proven in several studies, but so far only a few systematic attempts have been made to optimize weather- and circulation type classifications concerning their relationship to local PM10 concentrations. Against this background the aim of this study is to evaluate various approaches for the optimization of circulation type classifications with respect to their relevance for local PM10 concentrations in Bavarian cities (Germany) in order to detect those approaches that are best suited for the use in planned subsequent studies (e.g. estimation of potential PM10 variations due to future climate change). The used data set of daily mean PM10 has been provided by the Bavarian Environment Agency. For the analysed period 1980-2011 measurements of 16 urban traffic related stations, spread over the whole of Bavaria, are available. We provide initial characteristics of this data set concerning data availability, basic quality aspects, long

  2. Reduction of Local Stress Concentration on Nanosheet in Layered Nanoparticles with Water Molecules

    NASA Astrophysics Data System (ADS)

    Sato, Kiminori; Numata, Kazuomi; Fujimoto, Koichiro

    2014-01-01

    The local stress concentration on 2D nanosheets is investigated for saponite layered nanoparticles by means of X-ray diffraction (XRD) and positronium (Ps) annihilation spectroscopy. XRD experiments indicated that the layered structure for the mechanochemically milled sample is maintained in the presence of H2O molecules. Ps annihilation studies of self-assembly revealed that the 2D nanosheets are well in-plane ordered after uniaxial pressure compaction without H2O molecules due to the efficient propagation of stress concentration. The present results of both XRD and Ps lifetime spectroscopy clearly demonstrates that the stress concentration on the 2D nanosheets can be reduced in the presence of H2O molecules.

  3. Decline in the Development of New Anesthetics.

    PubMed

    Vlassakov, Kamen V; Kissin, Igor

    2016-05-01

    The number of new anesthetics approved by the USA FDA over the past 30 years (1985-2014) is much smaller than during the preceding 30 years (1955-1984): four versus ten. Investigational anesthetics clinically tested since 1990 have been almost exclusively intravenous anesthetics (nine compounds), with only one now approved by the FDA. All nine agents represent modifications of anesthetics introduced approximately 40-50 years ago; none demonstrates a truly novel mechanism of action. The apparent drought of novel anesthetics is difficult to explain. While there may be multiple reasons, we believe that one is especially noteworthy: the dramatic improvement in anesthesia safety owing to the context in which anesthetics are administered, effectively decreasing the pressure to develop new drugs with better safety margins. PMID:26922254

  4. Drosophila Social Clustering is Disrupted by Anesthetics and in narrow abdomen Ion Channel Mutants

    PubMed Central

    Burg, Elyssa D.; Langan, Sara T.; Nash, Howard A.

    2013-01-01

    Members of many species tend to congregate, a behavioral strategy known as local enhancement. Selective advantages of local enhancement range from efficient use of resources to defense from predators. While previous studies have examined many types of social behavior in fruit flies, few have specifically investigated local enhancement. Resource-independent local enhancement has recently been described in the fruit fly using a measure called social space index, although the neural mechanisms remain unknown. Here we analyze resource-independent local enhancement of Drosophila under conditions that allow us to elucidate its neural mechanisms. We have investigated the effects of general volatile anesthetics, compounds that compromise higher order functioning of the type typically required for responding to social cues. We exposed Canton-S flies to non-immobilizing concentrations of halothane and found that flies had a significantly decreased social space index compared to flies tested in air. Narrow abdomen (na) mutants, which display altered responses to anesthetics in numerous behavioral assays, also have a significantly reduced social space index, an effect that was fully reversed by restoring expression of na by driving a UAS-NA rescue construct with NA-GAL4. We found that na expression in cholinergic neurons fully rescued the behavioral defect, whereas expression of na in glutamatergic neurons did so only partially. Our results also suggest a role for na expression in the mushroom bodies, since suppressing na expression in the mushroom bodies of NA-GAL4 rescue flies diminishes social space index. Our data indicate that resource-independent local enhancement, a simple behavioral strategy, requires complex neural processing. PMID:23398613

  5. Direct measurement of local dissolved oxygen concentration spatial profiles in a cell culture environment.

    PubMed

    Kagawa, Yuki; Matsuura, Katsuhisa; Shimizu, Tatsuya; Tsuneda, Satoshi

    2015-06-01

    Controlling local dissolved oxygen concentration (DO) in media is critical for cell or tissue cultures. Various biomaterials and culture methods have been developed to modulate DO. Direct measurement of local DO in cultures has not been validated as a method to test DO modulation. In the present study we developed a DO measurement system equipped with a Clark-type oxygen microelectrode manipulated with 1 μm precision in three-dimensional space to explore potential applications for tissue engineering. By determining the microelectrode tip position precisely against the bottom plane of culture dishes with rat or human cardiac cells in static monolayer culture, we successfully obtained spatial distributions of DO in the medium. Theoretical quantitative predictions fit the obtained data well. Based on analyses of the variance between samples, we found the data reflected "local" oxygen consumption in the vicinity of the microelectrode and the detection of temporal changes in oxygen consumption rates of cultured cells was limited by the diffusion rate of oxygen in the medium. This oxygen measuring system monitors local oxygen consumption and production with high spatial resolution, and can potentially be used with recently developed oxygen modulating biomaterials to design microenvironments and non-invasively monitor local DO dynamics during culture. PMID:25565074

  6. Anesthetic consideration for nonintubated VATS

    PubMed Central

    Yang, Jen-Ting; Hung, Ming-Hui; Chen, Jin-Shing

    2014-01-01

    In the recent decade, nonintubated-intubated video-assisted thoracoscopic surgery (VATS) has been extensively performed and evaluated. The indicated surgical procedures and suitable patient groups are steadily increasing. Perioperative anesthetic management presents itself as a fresh issue for the iatrogenic open pneumothorax, which is intended for unilateral lung collapse to create a steady surgical field, and the ensuing physiologic derangement involving ventilatory and hemodynamic perspectives. With appropriate monitoring, meticulous employment of regional anesthesia, sedation, vagal block, and ventilatory support, nonintubated VATS is proved to be a safe alternative to the conventional intubated general anesthesia. PMID:24455170

  7. Contributions of local and regional sources of NO x to ozone concentrations in Southeast Texas

    NASA Astrophysics Data System (ADS)

    Zhang, Hongliang; Ying, Qi

    2011-06-01

    The Community Multi-scale Air Quality (CMAQ) model with a modified SAPRC-99 photochemical mechanism was used to investigate the contributions of local and upwind NO x sources to O 3 concentrations in Southeast Texas during the 2000 Texas Air Quality Study (TexAQS 2000) from August 25 to September 5, 2000. Contributions from eight different local NO x source types and eight different source regions to the 8-h average daytime O 3 concentrations from 1100 to 1800 CST (referred to as AD O 3 hereafter) are determined. Both diesel engines and highway gasoline vehicles account for 25 ppb of AD O 3 in the urban Houston area. NO x from natural gas combustion produces 35 ppb of AD O 3 in the industrial area of Houston. Contributions from industrial sources and coal combustion to AD O 3 have comparatively less broad spatial distribution with maximum values of 14 ppb and 20 ppb, respectively. Although the local sources are the most important sources, upwind sources have non-negligible influences (20-50%) on AD O 3 in the entire domain, with a maximum of 50 ppb in rural and coastal areas and 20 ppb in urban and industrial areas. To probe the origins of upwind sources contributions, NO x emissions in the entire eastern United States are divided into eight different regions and their contributions to O 3 concentrations in the Houston-Galveston-Brazoria (HGB) and Beaumont-Port Arthur (BPA) areas are determined. Among the various NO x source regions resolved in this study, other Texas counties near the HGB and BPA areas and southeastern states are the most important non-local sources of O 3. Under favorable transport conditions, emissions from neighbor states and northeastern states could also contribute to non-negligible O 3 concentrations (7-15%) in the HGB and BPA areas. This indicates that in addition to reduce local emissions, regional NO x emission controls, especially from the neighbor counties and states, are also necessary to improve O 3 air quality in Southeast Texas.

  8. Lidocaine Concentration in Oral Tissue by the Addition of Epinephrine.

    PubMed

    Tanaka, Eri; Yoshida, Kenji; Kawaai, Hiroyoshi; Yamazaki, Shinya

    2016-01-01

    The vasoconstrictive effect due to the addition of epinephrine to local anesthetic has been clearly shown by measuring blood-flow volume or blood anesthetic concentration in oral mucosal tissue. However, there are no reports on the measurement of anesthetic concentration using samples directly taken from the jawbone and oral mucosal tissue. Consequently, in this study, the effect of lidocaine concentration in the jawbone and oral mucosal tissue by the addition of epinephrine to the local anesthetic lidocaine was considered by quantitatively measuring lidocaine concentration within the tissue. Japanese white male rabbits (n = 96) were used as test animals. General anesthesia was induced by sevoflurane and oxygen, and then cannulation to the femoral artery was performed while arterial pressure was constantly recorded. Infiltration anesthesia was achieved by 0.5 mL of 2% lidocaine containing 1 : 80,000 epinephrine in the upper jawbone (E(+)) and 0.5 mL of 2% of epinephrine additive-free lidocaine (E(0)) under the periosteum. At specified time increments (10, 20, 30, 40, 50, and 60 minutes), samples from the jawbone, oral mucosa, and blood were collected, and lidocaine concentration was directly measured by high-performance liquid chromatography. No significant differences in the change in blood pressure were observed either in E(+) or E(0). In both E(+) and E(0) groups, the serum lidocaine concentration peaked 10 minutes after local anesthesia and decreased thereafter. At all time increments, serum lidocaine concentration in E(+) was significantly lower than that in E(0). There were no significant differences in measured lidocaine concentration between jawbone and mucosa within either the E(+) or the E(0) groups at all time points, although the E(0) group had significantly lower jawbone and mucosa concentrations than the E(+) group at all time points when comparing the 2 groups to each other. Addition of epinephrine to the local anesthetic inhibited systemic

  9. Variability of local PM10 mass concentrations in connection with blocking air circulation

    NASA Astrophysics Data System (ADS)

    Ştefan, Sabina; Roman, Iuliana

    2015-06-01

    The aim of this paper is to analyze the temporal variability of Particulate Matter mass concentrations in connection with air circulation, for eight rural sites situated in the Central and Eastern parts of Europe. The stations from Poland, Hungary and Romania are rural stations without sources of pollutants. The analysis covers four winters, between December 2004 and February 2008. The pollution episodes were selected to explain air circulation influence. The results show that the causes of pollution were local, due to high mean sea level pressure and the blocking, as air circulation on large scale, was dominant in the cases of enhanced pollution in the selected area.

  10. Volatile anesthetics inhibit sodium channels without altering bulk lipid bilayer properties

    PubMed Central

    Sanford, R. Lea; Lee, William; Schultz, Margaret F.; Ingólfsson, Helgi I.

    2014-01-01

    Although general anesthetics are clinically important and widely used, their molecular mechanisms of action remain poorly understood. Volatile anesthetics such as isoflurane (ISO) are thought to alter neuronal function by depressing excitatory and facilitating inhibitory neurotransmission through direct interactions with specific protein targets, including voltage-gated sodium channels (Nav). Many anesthetics alter lipid bilayer properties, suggesting that ion channel function might also be altered indirectly through effects on the lipid bilayer. We compared the effects of ISO and of a series of fluorobenzene (FB) model volatile anesthetics on Nav function and lipid bilayer properties. We examined the effects of these agents on Nav in neuronal cells using whole-cell electrophysiology, and on lipid bilayer properties using a gramicidin-based fluorescence assay, which is a functional assay for detecting changes in lipid bilayer properties sensed by a bilayer-spanning ion channel. At clinically relevant concentrations (defined by the minimum alveolar concentration), both the FBs and ISO produced prepulse-dependent inhibition of Nav and shifted the voltage dependence of inactivation toward more hyperpolarized potentials without affecting lipid bilayer properties, as sensed by gramicidin channels. Only at supra-anesthetic (toxic) concentrations did ISO alter lipid bilayer properties. These results suggest that clinically relevant concentrations of volatile anesthetics alter Nav function through direct interactions with the channel protein with little, if any, contribution from changes in bulk lipid bilayer properties. Our findings further suggest that changes in lipid bilayer properties are not involved in clinical anesthesia. PMID:25385786