1,721,186 research outputs found
Transmuscular quadratus lumborum (TQL) block for laparoscopic colorectal surgery: study protocol for a double-blind, prospective randomized placebo-controlled trial
No full textBACKGROUND: Thoracic epidural anesthesia is no longer considered the gold standard for perioperative analgesia in laparoscopic colorectal procedures. In the search for alternatives, the efficacy of the transverse abdominal plane (TAP) block and other abdominal wall blocks such as the transmuscular quadratus lumborum (TQL) block continues to be investigated for postoperative pain management. Most of the initial studies on TAP blocks reported positive effects; however, the amount of studies with negative outcomes is increasing, most probably due to the fact that the majority of abdominal wall blocks fail to mitigate visceral pain. The TQL block could prove attractive in the search for better postoperative pain relief after laparoscopic colorectal surgery. In several cadaveric studies of the TQL, a spread of dye into the thoracic paravertebral space, the intercostal spaces, and even the thoracic sympathetic trunk was reported. Given the advantage of possibly reaching the thoracic paravertebral space, the potential to reach nerves transmitting visceral pain, and the possible coverage of dermatomes T4-L1, we hypothesize that the TQL provides superior postoperative analgesia for laparoscopic colorectal surgery as compared to patient-controlled intravenous analgesia with morphine alone. METHODS AND DESIGN: In this prospective, randomized, double-blind controlled clinical trial, 150 patients undergoing laparoscopic colorectal surgery will be included. Patients will be randomly allocated to two different analgesic strategies: a bilateral TQL with 30 ml ropivacaine 0.375% each on both sides, administered before induction of anesthesia, plus postoperative patient-controlled intravenous analgesia with morphine (TQL group, n = 75), or a bilateral TQL block with 30 ml saline each on both sides plus postoperative patient-controlled intravenous analgesia with morphine (placebo group, n = 75). Our primary outcome parameter will be the morphine consumption during the first 24 h postsurgery. Secondary endpoints include pain intensity as assessed with the numerical rating scale (NRS) for pain, time to return of intestinal function (defined as the time to first flatus and the time to the first postoperative intake of solid food), time to first mobilization, the incidence of postoperative nausea and vomiting during the first 24 h, length of stay on the post anesthesia care unit (PACU) and in the hospital, the extent of sensory block at two time points (admission to and discharge from the PACU), the doses of morphine IV as requested by the patient from the PCA pump, the total dosage of morphine administered IV, the need for and dose of rescue analgesics (ketamine, clonidine), free plasma ropivacaine levels after induction and at discharge from the PACU, and the incidence of adverse events during treatment (in particular, signs of local anesthetic systemic toxicity (LAST)). Epidural analgesia is no longer the standard of care for postoperative analgesia in laparoscopic colorectal surgery. Until now, the most effective analgesic strategy in these patients especially in an enhanced recovery program is still unknown. Several abdominal wall blocks (TAP, fascia transversalis plane block) are known to have an analgesic effect only on somatic pain. Recognizing the importance of procedure-specific pain management, we aim to investigate whether a transmuscular quadratus lumborum block delivers superior pain control in comparison to patient-controlled intravenous analgesia with morphine alone. TRIAL REGISTRATION: EudraCT identifier 2019-002304-40. Registered on 17 September 2019.sponsorship: The study is funded by institutional departmental sources (Anesthesiology at the University Hospital Leuven) and additionally funded by the BARA (Belgian Association of Regional Anesthesia) board GRANT awarded at BARA 2019Sponsors details:UZ Leuven, Herestraat 49, 3000 Leuven, Belgium. Phone: 0032 (0) 16 33 22 11BARA vzw, BARA office UZ Leuven Department Anesthesia, Herestraat 49, 3000 Leuven. Phone 0032 (0) 16 34 86 52 (Anesthesiology at the University Hospital Leuven, BARA (Belgian Association of Regional Anesthesia) board GRANT, UZ Leuven, Herestraat, Leuven, Belgium, BARA vzw, BARA office UZ Leuven Department Anesthesia, Herestraat, Leuven)status: Publishe
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Einfluss dreier verschiedener Techniken der extrakorporalen Zirkulation auf Parameter der Hämodynamik, Inflammation, Blutgerinnung und Hämolyse bei aortokoronaren Bypass-Operationen : die konventionelle Herz-Lungen-Maschine im Vergleich mit zwei miniaturisierten Bypass-Systemen
No full textThe use of cardiopulmonary bypass circuits (CPB) in cardiac surgery may be associated with several adverse effects, e.g. systemic inflammatory response syndrome, hemolysis, hemodilution, coagulopathy, global hemodynamic dysfunction. These adverse effects occur due to the contact of blood with non-endothelial surfaces and air, intraoperative hypothermia, hemodilution as the result of bypass priming and traumatization of blood cells by the different blood pumps. We hypothesized that by reducing foreign surface area and extracorporeal volume, the use of miniaturized bypass systems and the avoidance of intraoperative hypothermia could reduce the adverse effects. In this prospective, randomized controlled trial, we therefore compared the use of two different simplified bypass systems (SBS) in patients undergoing normothermic on-pump beating heart coronary artery bypass grafting (CABG) with the use of a conventional CPB (cCPB) circuit in patients undergoing CABG with hypothermic cardioplegic arrest. The goal of the study was to study the influences of the three different bypass circuits on global hemodynamics and parameters of inflammation, coagulation and hemolysis and on clinical outcome parameters. The patients were randomly assigned to three groups: 15 patients were operated with a cCPB circuit in moderate hypothermia. Cardiac arrest was induced by cold crystalloid cardioplegic solution. Two groups of 15 patients each underwent beating heart surgery in normothermia with assistance of two different SBS, both with a reduction of the extracorporeal priming volume, and one with an additional reduction of the foreign surface area. Hemodynamic variables were assessed with transpulmonary thermodilution. Plasma levels of pro-inflammatory and anti-inflammatory mediators and parameters of coagulation and hemolysis were measured perioperatively. Neither the isolated reduction of the extracorporeal priming volume nor the additional reduction of the foreign surface area in SBS had beneficial effects on global hemodynamics. Moreover, the use of SBS could not reduce the systemic inflammatory response. In contrast, only patients in the cCPB-group showed a significant increase of plasma levels of anti-inflammatory mediators (interleukin-10). As a marker of hemolysis, free hemoglobin concentrations were significantly elevated in the cCPB group. Also with regard to coagulation parameters, D-Dimer levels were increased only in the cCPB-group. However, other coagulation parameters, perioperative blood loss and transfusion requirements did not differ significantly between the three groups. In conclusion, neither the reduction of the extracorporeal priming volume nor of the foreign surface area by the SBS were able to improve global hemodynamics and to attenuate the perioperative pro-inflammatory response
Einfluss dreier verschiedener Techniken der extrakorporalen Zirkulation auf Parameter der Hämodynamik, Inflammation, Blutgerinnung und Hämolyse bei aortokoronaren Bypass-Operationen : die konventionelle Herz-Lungen-Maschine im Vergleich mit zwei miniaturisierten Bypass-Systemen
No full textThe use of cardiopulmonary bypass circuits (CPB) in cardiac surgery may be associated with several adverse effects, e.g. systemic inflammatory response syndrome, hemolysis, hemodilution, coagulopathy, global hemodynamic dysfunction. These adverse effects occur due to the contact of blood with non-endothelial surfaces and air, intraoperative hypothermia, hemodilution as the result of bypass priming and traumatization of blood cells by the different blood pumps. We hypothesized that by reducing foreign surface area and extracorporeal volume, the use of miniaturized bypass systems and the avoidance of intraoperative hypothermia could reduce the adverse effects. In this prospective, randomized controlled trial, we therefore compared the use of two different simplified bypass systems (SBS) in patients undergoing normothermic on-pump beating heart coronary artery bypass grafting (CABG) with the use of a conventional CPB (cCPB) circuit in patients undergoing CABG with hypothermic cardioplegic arrest. The goal of the study was to study the influences of the three different bypass circuits on global hemodynamics and parameters of inflammation, coagulation and hemolysis and on clinical outcome parameters. The patients were randomly assigned to three groups: 15 patients were operated with a cCPB circuit in moderate hypothermia. Cardiac arrest was induced by cold crystalloid cardioplegic solution. Two groups of 15 patients each underwent beating heart surgery in normothermia with assistance of two different SBS, both with a reduction of the extracorporeal priming volume, and one with an additional reduction of the foreign surface area. Hemodynamic variables were assessed with transpulmonary thermodilution. Plasma levels of pro-inflammatory and anti-inflammatory mediators and parameters of coagulation and hemolysis were measured perioperatively. Neither the isolated reduction of the extracorporeal priming volume nor the additional reduction of the foreign surface area in SBS had beneficial effects on global hemodynamics. Moreover, the use of SBS could not reduce the systemic inflammatory response. In contrast, only patients in the cCPB-group showed a significant increase of plasma levels of anti-inflammatory mediators (interleukin-10). As a marker of hemolysis, free hemoglobin concentrations were significantly elevated in the cCPB group. Also with regard to coagulation parameters, D-Dimer levels were increased only in the cCPB-group. However, other coagulation parameters, perioperative blood loss and transfusion requirements did not differ significantly between the three groups. In conclusion, neither the reduction of the extracorporeal priming volume nor of the foreign surface area by the SBS were able to improve global hemodynamics and to attenuate the perioperative pro-inflammatory response
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