Search

Recent recommendations describe a set of core anatomical structures to identify on ultrasound for the performance of basic blocks in ultrasound-guided regional anesthesia (UGRA). This project aimed to generate consensus recommendations for core structures to identify during the performance of intermediate and advanced blocks. An initial longlist of structures was refined by an international panel of key opinion leaders in UGRA over a three-round Delphi process. All rounds were conducted virtually and anonymously. Blocks were considered twice in each round: for "orientation scanning" (the dynamic process of acquiring the final view) and for "block view" (which visualizes the block site and is maintained for needle insertion/injection). A "strong recommendation" was made if ≥75% of participants rated any structure as "definitely include" in any round. A "weak recommendation" was made if >50% of participants rated it as "definitely include" or "probably include" for all rounds, but the criterion for strong recommendation was never met. Structures which did not meet either criterion were excluded. Forty-one participants were invited and 40 accepted; 38 completed all three rounds. Participants considered the ultrasound scanning for 19 peripheral nerve blocks across all three rounds. Two hundred and seventy-four structures were reviewed for both orientation scanning and block view; a "strong recommendation" was made for 60 structures on orientation scanning and 44 on the block view. A "weak recommendation" was made for 107 and 62 structures, respectively. These recommendations are intended to help standardize teaching and research in UGRA and support widespread and consistent practice. [ABSTRACT FROM AUTHOR]

Background/importance There is heterogeneity among the outcomes used in regional anesthesia research. Objective We aimed to produce a core outcome set for regional anesthesia research. Methods We conducted a systematic review and Delphi study to develop this core outcome set. A systematic review of the literature from January 2015 to December 2019 was undertaken to generate a long list of potential outcomes to be included in the core outcome set. For each outcome found, the parameters such as the measurement scale, timing and definitions, were compiled. Regional anesthesia experts were then recruited to participate in a three-round electronic modified Delphi process with incremental thresholds to generate a core outcome set. Once the core outcomes were decided, a final Delphi survey and video conference vote was used to reach a consensus on the outcome parameters. Results Two hundred and six papers were generated following the systematic review, producing a long list of 224 unique outcomes. Twenty-one international regional anesthesia experts participated in the study. Ten core outcomes were selected after three Delphi survey rounds with 13 outcome parameters reaching consensus after a final Delphi survey and video conference. Conclusions We present the first core outcome set for regional anesthesia derived by international expert consensus. These are proposed not to limit the outcomes examined in future studies, but rather to serve as a minimum core set. If adopted, this may increase the relevance of outcomes being studied, reduce selective reporting bias and increase the availability and suitability of data for meta-analysis in this area. [ABSTRACT FROM AUTHOR]

Background: The primary aim of this study was to compare the long-term functional outcome of midshaft clavicle fracture fixation for delayed (≥3 month) and non-union (≥6 month) compared to a matched cohort of patients that achieved union with non-operative management. The secondary aim was to assess cost-effectiveness of fixation. Methods: A consecutive series of patients over 10-years were retrospectively reviewed using the QuickDASH, Oxford Shoulder Score and EuroQol five-dimension summary index (EQ-5D). These patients were compared to a matched cohort that achieved union after non-operative management using propensity score matching. Results: Sixty patients (follow-up 79%, n = 60/76) at 4.1 years post-operative (1.1–10.0 years) had a QuickDASH of 16.5 (95% CI 11.6–21.5), Oxford Shoulder Score 41.5 (39.0–44.1) and EQ-5D 0.7621 (0.6822–0.8421). One in five patients were dissatisfied with their final outcome (n = 13/60). Functional outcome was inferior following fixation when compared to patients that united with non-operative management (QuickDASH 16.5 vs. 5.5, p < 0.001 and EQ-5D 0.7621 vs. 0.9073, p = 0.001). However, significant improvements were found when compared to pre-operative scores (QuickDASH p < 0.001 and EQ-5D p < 0.001). The cost per QALY for fixation was £5624.62 for the study cohort. Conclusions: Clavicle fixation for delayed and non-union is a cost-effective intervention but outcomes are worse compared to patients that unite with non-operative management. [ABSTRACT FROM AUTHOR]

There is no universally agreed set of anatomical structures that must be identified on ultrasound for the performance of ultrasound-guided regional anesthesia (UGRA) techniques. This study aimed to produce standardized recommendations for core (minimum) structures to identify during seven basic blocks. An international consensus was sought through a modified Delphi process. A long-list of anatomical structures was refined through serial review by key opinion leaders in UGRA. All rounds were conducted remotely and anonymously to facilitate equal contribution of each participant. Blocks were considered twice in each round: for "orientation scanning" (the dynamic process of acquiring the final view) and for the "block view" (which visualizes the block site and is maintained for needle insertion/injection). Strong recommendations for inclusion were made if ≥75% of participants rated a structure as "definitely include" in any round. Weak recommendations were made if >50% of participants rated a structure as "definitely include" or "probably include" for all rounds (but the criterion for "strong recommendation" was never met). Thirty-six participants (94.7%) completed all rounds. 128 structures were reviewed; a "strong recommendation" is made for 35 structures on orientation scanning and 28 for the block view. A "weak recommendation" is made for 36 and 20 structures, respectively. This study provides recommendations on the core (minimum) set of anatomical structures to identify during ultrasound scanning for seven basic blocks in UGRA. They are intended to support consistent practice, empower non-experts using basic UGRA techniques, and standardize teaching and research. [ABSTRACT FROM AUTHOR]

Reclaimed carbon fiber materials were studied in this paper with the aim of improving virgin fiber feedstock usage. Both processing and mechanical properties were investigated. The compaction response showed lower fiber volume fractions in reclaimed fiber materials than the virgin continuous reinforcement from which it was reclaimed. In addition, localized high-strain regions were observed during consolidation of the dry fiber and mechanical loading of cured laminates. These vulnerable failure points were mitigated by incorporating virgin continuous fiber feedstock into the laminate. A knock-down in mechanical properties was observed, however classical laminated plate theory identified a planar stiffness drop of 3.5 GPa for every 10% increase in reclaimed carbon fiber content in a continuous fiber laminate. Increased feedstock usage by combining both virgin and reclaimed carbon fibers was shown to be viable option to implement more resource efficient, but heavier, composite structures. [ABSTRACT FROM AUTHOR]

Background and Objectives: Ipsilateral phrenic nerve palsy (PNP) is an undesirable side of conventional approaches to interscalene brachial plexus blocks. The purpose of this study was to demonstrate whether or not the phrenic nerve can be spared by dye when injected at the division of the upper trunk of the brachial plexus.Methods: Under ultrasound guidance, 5 mL of radiolabeled dye was injected between the anterior and posterior division of the upper trunk in two fresh, cryopreserved cadavers. CT scan analysis, cadaveric dissection, and cryosectioning were performed to examine the spread of the injectate.Results: We found staining of the injectate over the entire upper trunk with its anterior and posterior divisions, the suprascapular nerve under the omohyoid muscle and the lateral pectoralis nerve, and the C5 and C6 roots. The middle trunk was partially stained. There was no evidence of dye staining of the lower trunk, anterior aspect of the anterior scalene muscle, or the phrenic nerve.Conclusions: Our study offers an anatomical basis for the possibility of providing shoulder analgesia and avoiding a PNP. [ABSTRACT FROM AUTHOR]

The ability to confidently estimate the depths of small-to-medium sized (3.5 ≤ mb ≤ 5.5) seismic disturbances is important both in plate tectonics studies, and when monitoring compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Seismic source depths can be determined by identification of the teleseismic depth phases pP and sP, and also by modelling surface wave amplitude spectra. The radiation pattern of the teleseismic depth phase pP and fundamental mode Rayleigh amplitudes show that the effectiveness of these methods of earthquake depth estimation is dependent on the orientation of the focal mechanism and the station locations. For some focal mechanisms, the predicted amplitude of the teleseismic depth phase pP will only be large for stations in certain locations, and the Rayleigh wave spectral nulls that tightly constrain the seismic source depth when modelling surface wave amplitude spectra often only occur for a limited range of azimuths. In this study, we show that for sources where Rayleigh wave spectral nulls are not observed and the source depth cannot be constrained using the surface wave amplitude spectra, the focal mechanism obtained by modelling Rayleigh and Love wave amplitude spectra can be used to identify the locations of stations where pP should have a large amplitude and hence be easiest for an analyst to identify. The increased global coverage of seismometer stations means that there is an increased likelihood that stations exist in the locations where the predicted amplitude of pP is large. As the identified depth phases are consistent with the focal mechanism this approach allows increased confidence to be placed in the identified depth phases and hence the estimated source depth. This approach could potentially be used with other methods of focal mechanism estimation provided that the method used to estimate the focal mechanism is independent of the source depth. [ABSTRACT FROM AUTHOR]

The 2008 February 27 Market Rasen (UK) earthquake is used to show how earthquake source parameters can be estimated using a multi-objective optimization approach to the joint inversion of teleseismic body wave and regional surface wave observations. To estimate the source depth, short-period teleseismic seismograms are interpreted in terms of P and the depth phases pP and sP using the F-statistic and its associated probability theory. Results of this analysis are inconclusive as two possible source depths are identified. To identify our preferred depth, a method of estimating source depth and mechanism by modelling surface wave amplitude spectra is applied to data recorded at regional distances. A source depth of 22 km is found to be consistent with the observed body and surface waves. Upper and lower amplitude bounds and polarities are then placed on the phases interpreted as P, pP and sP for a source depth of 22 km. The Gaussian relative amplitude method is used to calculate a likelihood for all possible orientations of the double-couple source. A multi-objective optimization approach can then used to compare these likelihoods with calculated misfits between observed and synthetic surface wave amplitude spectra for all orientations of the double-couple source. Our preferred focal mechanism ( and ) is found by normalizing and summing both misfits to find the focal mechanism with the lowest combined misfit. Synthetic body wave seismograms, surface wave amplitude spectra and seismograms are in good agreement with the observed data for our preferred focal mechanism and depth. [ABSTRACT FROM AUTHOR]