501 research outputs found
Lipid rescue: the use of lipid emulsions to treat local anaesthetic toxicity
Despite increasing safety of regional anaesthesia, the growth in the popularity therof implies that local anaesthetic toxicity will occur occasionally. Local anaesthetic cardiotoxicity, even when using “safer” modern local anaesthetics, is notoriously resistant to standard resuscitation. The aim of this paper is to review current knowledge regarding the use of lipid emulsions to treat local anaesthetic toxicity.Keywords: lipid emulsion therapy; local anaesthetic toxicity; local anaesthetic cardiotoxicity; cardiopulmonary resuscitation; bupivacaine cardiotoxicit
Xylocaine® 10% Pump Spray as topical anaesthetic for venepuncture pain
Background: Cutaneous analgesia for venepuncture pain can be achieved using various topically applied local anaesthetic formulations. Xylocaine®10% Pump Spray containing lignocaine hydrochloride and 95% ethanol is exclusively recommended for mucosal anaesthesia. However, this formulation is readily able to penetrate skin. This study investigated whether topical pretreatment with Xylocaine® 10% Pump Spray could facilitate analgesia for venepuncture.Methods: A single-centre, prospective, randomised, double-blind placebo-controlled trial was conducted. One hundred patients were enrolled. The control and intervention groups had 0.5 ml saline and 0.5 ml Xylocaine®applied for 20 min to preselected venepuncture sites. Pain associated with an 18-gauge cannula venepuncture was rated on an 11-point Numerical Rating Scale. A two-point or 30% reduction in pain would be deemed clinically significant.Results: Pain scores were lower (p= 0.001) in the Xylocaine® (median 2; 95% CI 2–3) than the saline (median 4; 95% CI 3–5) group. Moderate-to-severe pain occurred in fewer Xylocaine® (18%) than saline (42%) treated patients (relative risk 0.43, CI 0.22 to 0.48; NNT = 5).Conclusion:Topical Xylocaine®10% Pump Spray pre-treatment provided a time-effective method of reducing venepuncture associated pain.Keywords:local anaesthesia, venepuncture pain, Xylocaine® 10% Pump Spra
Sevoflurane or halothane with target-controlled sufentanil infusions for coronary artery bypass surgery
Objectives: Comparison of hemodynamics, circulatory efficiency, myocardial ischemia and recall during and after sevoflurane or halothane (0.6 MAC {Minimum Alveolar Concentration} inspired) combined with a target-controlled sufentanil infusion (2 ng.ml-1) for coronary artery bypass grafting. Methods: Prospective randomised non-blinded study in a university teaching hospital of 45 patients undergoing on-pump surgery. Inhalation anesthetic agent was delivered before, during and after cardiopulmonary bypass. Results: Intraoperative hemodynamics were maintained within predetermined limits using vasoactive and cardioactive drugs. Heart rate was unchanged from baseline, however the sevoflurane-sufentanil group required more glycopyrrollate, indicating a tendency towards a slower heart rate. In both groups, similar low incidences of myocardial ischemia were detected. After induction of anesthesia, as well as intraoperatively, oxygen consumption decreased by up to 36.6% compared with the awake values in both groups. Oxygen delivery remained unchanged during all measuring periods. Mixed venous oxygen tensions rose after induction, even in patients with cardiac indices below 2.2 L.min-1.m-2, indicating maintenance of an effective circulation when utilising these techniques. Twelve hours postoperatively, oxygen consumption exceeded awake values by 31%. No explicit recall was reported by any patient on enquiry on the third postoperative day. Conclusions: Low concentrations of sevoflurane or halothane, supplementing target-controlled sufentanil infusions, were both suitable for providing anesthesia for coronary bypass surgery.Keywords: Coronary artery bypass grafting, anesthesia, hemodynamics, sevoflurane, halothane, sufentanil, mixed venous oxygen tension, oxygen consumption, balanced anesthesi
On a two Pomeron description of the F_2 structure function
We perform a global fit to the inclusive structure function considering a QCD
inspired model describing the ep scattering. In lines of a two Pomeron
approach, the structure function F_2 has a hard piece given by the model and
the remaining soft contributions: the soft Pomeron and non-singlet content. We
have investigated several choices for the soft Pomeron and its implication in
the data description. In particular, we carefully estimated the relative role
of the hard and the soft contributions in a large span of x and Q^2.Comment: 14 pages, 3 figures. To be published in Eur. Phys. J.
On possible implications of gluon number fluctuations in DIS data
We study the effect of gluon number fluctuations (Pomeron loops) on deep
inelastic scattering (DIS) in the fixed coupling case. We find that the
description of the DIS data is improved once gluon number fluctuations are
included. Also the values of the parameters, like the saturation exponent and
the diffussion coefficient, turn out reasonable and agree with values obtained
from numerical simulations of toy models which take into account fluctuations.
This outcome seems to indicate the evidence of geometric scaling violations,
and a possible implication of gluon number fluctuations, in the DIS data.
However, we cannot exclude the possibility that the scaling violations may also
come from the diffusion part of the solution to the BK-equation, instead of
gluon number fluctuations.Comment: 9 pages, 2 figures; references added, minor changes, matches
published versio
Extension of the JIMWLK Equation in the Low Gluon Density Region
It has recently been realized that the Balitsky-JIMWLK equations have serious
shortcomings as equations to be used in small-x evolution near the unitarity
limit. A recent generalization of the Balitsky equations has been given which
corrects these shortcomings. In this paper we present an equivalent discussion,
but in terms of the JIMWLK equation where we show that a new (fourth order
functional derivative) term should be included. We also present a stochastic
version of the new equation which, however, has some unusual mathematical
aspects which are not as yet well understood.Comment: 23 pages, 1 figure, corrected typos, corrected references, published
versio
Small-x physics beyond the Kovchegov equation
We note the differences between the Kovchegov equation and the
Balitsky-JIMWLK equations as methods of evaluating high energy hard scattering
near the unitarity limit. We attempt to simulate some of the correlations
absent in the Kovchegov equation by introducing two boundaries rather than the
single boundary which effectively approximates the unitarity limit guaranteed
in the Kovchegov equation. We solve the problem of BFKL evolution in the
presence of two boundaries and note that the resulting T-matrix now is the same
in different frames, which was not the case in the single boundary case. The
scaling behavior of the solution to the Kovchegov equation is apparently now
lost.Comment: 38 pages, 8 figures, typos correcte
Adsorbate vibrational modes enhancement of radiative heat transfer and van der Waals friction
We study the dependence of the heat transfer and the van der Waals friction
between two semi-infinite solids on the dielectric properties of the bodies. We
show that the heat transfer and van der Waals friction at short separation
between the solids may increase by many orders of magnitude when the surfaces
are covered by adsorbates, or can support low-frequency surface plasmons. In
this case the heat transfer and van der Waals friction are determined by
resonant photon tunneling between adsorbate vibrational modes, or surface
plasmon modes. The enhancement of the van der Waals friction is especially
large when in the adsorbed layer there is an acoustic branch for the vibrations
parallel to the surface like in the case of Cs adsorption on Cu(100) surface.
In this case we show that even for separation nm, the van der Waals
friction induced by adsorbates can be so large that it can be measured with the
present state-of-art equipment. The van an der Waals friction is characterized
by a strong distance dependence (), and at the small distances it
can be much larger than \textit{the electrostatic} friction observed in
\cite{Stipe}. \vskip 0.3cm \textit{Keywords}: non-contact friction, van der
Waals friction, radiative heat transfer, atomic force microscope, adsorbate
vibrational modeComment: published in Surface Scienc
Two parton shower background for associate W Higgs production
The estimates of the background for the associate W Higgs production, which
stems from the two parton shower production. It is about 1 - 2.5 times larger
than the signal. However, this background does not depend on the rapidity
difference between the W and the pair, while the signal peaks when
the rapidity difference is zero. The detailed calculations for the enhanced
diagrams' contribution to this process, are presented, and it is shown that the
overlapping singularities, being important theoretically, lead to a negligible
contribution for the LHC range of energiesComment: 35 pages and 10 figures in eps file
Interactions, Distribution of Pinning Energies, and Transport in the Bose Glass Phase of Vortices in Superconductors
We study the ground state and low energy excitations of vortices pinned to
columnar defects in superconductors, taking into account the long--range
interaction between the fluxons. We consider the ``underfilled'' situation in
the Bose glass phase, where each flux line is attached to one of the defects,
while some pins remain unoccupied. By exploiting an analogy with disordered
semiconductors, we calculate the spatial configurations in the ground state, as
well as the distribution of pinning energies, using a zero--temperature Monte
Carlo algorithm minimizing the total energy with respect to all possible
one--vortex transfers. Intervortex repulsion leads to strong correlations
whenever the London penetration depth exceeds the fluxon spacing. A pronounced
peak appears in the static structure factor for low filling fractions . Interactions lead to a broad Coulomb gap in the distribution of
pinning energies near the chemical potential , separating
the occupied and empty pins. The vanishing of at leads to a
considerable reduction of variable--range hopping vortex transport by
correlated flux line pinning.Comment: 16 pages (twocolumn), revtex, 16 figures not appended, please contact
[email protected]
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