2,212 research outputs found
Designing the ideal perioperative pain management plan starts with multimodal analgesia.
Multimodal analgesia is defined as the use of more than one pharmacological class of analgesic medication targeting different receptors along the pain pathway with the goal of improving analgesia while reducing individual class-related side effects. Evidence today supports the routine use of multimodal analgesia in the perioperative period to eliminate the over-reliance on opioids for pain control and to reduce opioid-related adverse events. A multimodal analgesic protocol should be surgery-specific, functioning more like a checklist than a recipe, with options to tailor to the individual patient. Elements of this protocol may include opioids, non-opioid systemic analgesics like acetaminophen, non-steroidal anti-inflammatory drugs, gabapentinoids, ketamine, and local anesthetics administered by infiltration, regional block, or the intravenous route. While implementation of multimodal analgesic protocols perioperatively is recommended as an intervention to decrease the prevalence of long-term opioid use following surgery, the concurrent crisis of drug shortages presents an additional challenge. Anesthesiologists and acute pain medicine specialists will need to advocate locally and nationally to ensure a steady supply of analgesic medications and in-class alternatives for their patients\u27 perioperative pain management
Low-momentum interactions for nuclei
We show how the renormalization group is used to construct a low-momentum
nucleon-nucleon interaction V_{low k}, which unifies all potential models used
in nuclear structure calculations. V_{low k} can be directly applied to the
nuclear shell model or to nucleonic matter without a G matrix resummation. It
is argued that V_{low k} parameterizes a high-order chiral effective field
theory two-nucleon force. We use cutoff dependence as a tool to assess the
error in the truncation of nuclear forces to two-nucleon interactions and
introduce a low-momentum three-nucleon force, which regulates A=3,4 binding
energies. The adjusted three-nucleon interaction is perturbative for small
cutoffs. In contrast to other precision interactions, the error due to missing
many-body forces can be estimated, when V_{low k} and the corresponding
three-nucleon force are used in nuclear structure calculations and the cutoff
is varied.Comment: 10 pages, 5 figures, talk at INT workshop on Nuclear Forces and the
Quantum Many-Body Problem, Seattle, October 200
In-Medium Similarity Renormalization Group for Nuclei
We present a new ab-initio method that uses similarity renormalization group
(SRG) techniques to continuously diagonalize nuclear many-body Hamiltonians. In
contrast with applications of the SRG to two- and three-nucleon interactions in
free space, we perform the SRG evolution "in medium" directly in the -body
system of interest. The in-medium approach has the advantage that one can
approximately evolve -body operators using only two-body machinery
based on normal-ordering techniques. The method is nonperturbative and can be
tailored to problems ranging from the diagonalization of closed-shell nuclei to
the construction of effective valence shell-model Hamiltonians and operators.
We present first results for the ground-state energies of He, O and
Ca, which have accuracies comparable to coupled-cluster calculations.Comment: 4pages, 4 figures, to be published in PR
Quantum Monte Carlo calculations of neutron matter with chiral three-body forces
Chiral effective field theory (EFT) enables a systematic description of
low-energy hadronic interactions with controlled theoretical uncertainties. For
strongly interacting systems, quantum Monte Carlo (QMC) methods provide some of
the most accurate solutions, but they require as input local potentials. We
have recently constructed local chiral nucleon-nucleon (NN) interactions up to
next-to-next-to-leading order (NLO). Chiral EFT naturally predicts
consistent many-body forces. In this paper, we consider the leading chiral
three-nucleon (3N) interactions in local form. These are included in auxiliary
field diffusion Monte Carlo (AFDMC) simulations. We present results for the
equation of state of neutron matter and for the energies and radii of neutron
drops. In particular, we study the regulator dependence at the Hartree-Fock
level and in AFDMC and find that present local regulators lead to less
repulsion from 3N forces compared to the usual nonlocal regulators.Comment: 10 pages, 8 figures, 1 table, published versio
From low-momentum interactions to nuclear structure
We present an overview of low-momentum two-nucleon and many-body interactions
and their use in calculations of nuclei and infinite matter. The softening of
phenomenological and effective field theory (EFT) potentials by renormalization
group (RG) transformations that decouple low and high momenta leads to greatly
enhanced convergence in few- and many-body systems while maintaining a
decreasing hierarchy of many-body forces. This review surveys the RG-based
technology and results, discusses the connections to chiral EFT, and clarifies
various misconceptions.Comment: 76 pages, 57 figures, two figures updated, published versio
Identifying hybridizing taxa within the Daphnia longispina species complex: a comparison of genetic methods and phenotypic approaches
Daphnia galeata Sars, D. longispina O. F. Muller and D. cucullata Sars (Crustacea: Cladocera) are closely related species which often produce interspecific hybrids in natural populations. Several marker systems are available for taxon determination in this hybridizing complex, but their performance and reliability has not been systematically assessed. We compared results from identifications by three molecular methods. More than 1,200 individuals from 10 localities in the Czech Republic were identified as parental species or hybrids by allozyme electrophoresis and the analysis of the restriction fragment length polymorphism of the internal transcribed spacer (ITS-RFLP); over 440 of them were additionally analyzed and identified by 12 microsatellite loci. Identification by microsatellite markers corresponded well with allozyme analyses. However, consistent discrepancies between ITS-RFLP and other markers were observed in two out of 10 studied localities. Although some marker discrepancies may have been caused by occasional recent introgression, consistent deviations between ITS-RFLP and other markers suggest a long-term maintenance of introgressed alleles. These results warn against its use as a sole identification method in field studies. Additionally, we quantitatively evaluated the discriminatory power of geometric morphometric (elliptic Fourier) analysis of body shapes based on photos of over 1,300 individuals pre-classified by allozyme markers. Furthermore, a randomly selected subset of 240 individuals was independently determined from photos by several experts. Despite a tendency for morphological divergence among parental Daphnia species, some taxa (especially D. galeata, D. longispina, and their hybrids) substantially overlapped in their body shapes. This was reflected in different determination success for particular species and hybrids in discriminant analysis based on shape data as well as from photograph
Managing Prolonged Pain After Surgery: Examining the Role of Opioids.
A notable minority of patients experience persistent postsurgical pain and some of these patients consequently have prolonged exposure to opioids. Risk factors for prolonged opioid use after surgery include preoperative opioid use, anxiety, substance abuse, and alcohol abuse. The window to intervene and potentially prevent persistent opioid use after surgery is short and may best be accomplished by both surgeon and anesthesiologist working together. Anesthesiologists in particular are well positioned in the perioperative surgical home model to affect multiple aspects of the perioperative experience, including tailoring intraoperative medications and providing consultation for possible discharge analgesic regimens that can help minimize opioid use. Multimodal analgesia protocols reduce opioid consumption and thereby reduce exposure to opioids and theoretically the risk of persistent use. Regional anesthesia and analgesia techniques also reduce opioid consumption. Although many patients will recover without difficulty, the small minority who do not should receive customized care which may involve multiple office visits or consultation of a pain specialist. Enhanced recovery pathways are useful in optimizing outcomes after surgery
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