1,721,032 research outputs found
When, where and how to initiate hypothermia after adult cardiac arrest
No full textTherapeutic hypothermia (TH) has been shown to improve neurological outcome and survival after witnessed
cardiac arrest (CA) that is due to ventricular "brillation. Although TH is widely used following witnessed CA as well
as all forms of initial rhythm, the mortality rate after CA remains unacceptably high, and additional study is needed
to understand when and how to implement hypothermia in the post-resuscitation phase. Experimental studies have
emphasized the importance of initiating cooling soon after the return of spontaneous circulation (ROSC) or even
during cardiopulmonary resuscitation (CPR). Clinical studies have shown that pre-hospital induction of hypothermia
is feasible and has no major adverse events—even when used intra-arrest—and may provide some additional
bene"ts compared to delayed in-hospital cooling. !us, hypothermia use should not be limited to the Intensive Care
Unit but can be initiated in the "eld/ambulance or in the Emergency Department, then continued after hospital
admission— even during speci"c procedures such as coronary angiography—as part of the global management of
CA patients. Various methods (both non-invasive and invasive) are available to achieve and maintain the target
temperature; however, only some of these methods—which include cold #uids, ice packs, iced pads and helmet and
trans-nasal cooling— are easily deployed in the pre-hospital setting
Brain perfusion in sepsis.
No full textBrain dysfunction is a frequent complication of sepsis, usually defined as “sepsis-associated encephalopathy” (SAE). Its pathophysiology is complex and related to numerous processes and pathways, while the exact mechanisms pro- ducing neurological impairment in septic patients remain incompletely elucidated. Alterations of the cerebral blood flow (CBF) may represent a key component for the development of SAE. Reduction of CBF may be caused by cerebral vaso- constriction, either induced by inflammation or hypocapnia. Endothelial dysfunction associated with sepsis leads to im- pairment of microcirculation and cerebral metabolic uncoupling that may further reduce brain perfusion so that CBF be- comes inadequate to satisfy brain cellular needs. The natural autoregulatory mechanisms that protect the brain from re- duced/inadequate CBF can be impaired in septic patients, especially in those with shock or delirium, and this further con- tributes to cerebral ischemia if blood pressure drops below critical thresholds. Sedative agents alter cerebro-vascular reac- tivity and may significantly reduce CBF. Although disorders of brain perfusion and alteration of CBF and cerebral autoregulation are frequently observed in humans with sepsis, their exact role in the pathogenesis of SAE remains un- known. Brain perfusion can further become inadequate due to cerebral microcirculatory dysfunction, as evidenced in the experimental setting. Microvascular alterations can be implicated in the development of electrophysiological abnormali- ties observed during sepsis and contribute to neurological alterations in septic animals. The aim of this review is to pro- vide an update on the pathophysiology of brain perfusion in sepsis, with a particular focus on human clinical investigation and novel tools for CBF monitoring in septic patients
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
Author reply to: can transthoracic echocardiography be used as a reference method for cardiac output measurement?
Full text linkCommentLetterResearch Support, Non-U.S. Gov'tSCOPUS: le.jinfo:eu-repo/semantics/publishe
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
Brain injury after cardiac surgery
No full textIn patients undergoing cardiac surgery, postoperative brain injury significantly contributes to increase morbidity and mortality and has negative consequences on quality of life and costs. Moreover, over the past years, compelling medical and technological improvements have allowed an even older patients' population, with several comorbidities, to be treated with cardiac surgery; however, the risk of brain injury after such interventions is also increased in these patients. With the aim of improving post-operative neurological outcome, a variety of neuromonitoring methods and devices have been introduced in clinical practice. These techniques allow the assessment of a number of parameters, such as cerebral blood flow, brain embolic events, cerebral cortical activity, depth of anesthesia and brain oxygenation. Some of them have been used to optimize the hemodynamic management of such patients and to select specific therapeutic interventions. Also, various pharmacological and non-pharmacological approaches have been proposed to minimize the incidence of brain injury in this setting. In this review we describe the risk factors and mechanisms of cerebral injury after cardiac surgery and focus on monitoring techniques and clinical strategies that could help clinicians to minimize the incidence of brain injury
Myocardial depression in sepsis: from pathogenesis to clinical manifestations and treatment.
No full textThe cardiovascular system plays a key role in sepsis, and septic myocardial depression is a common finding associated with increased morbidity and mortality. Myocardial depression during sepsis is not clearly defined, but it can perhaps be best described as a global (systolic and diastolic) dysfunction of both the left and right sides of the heart. The pathogenesis of septic myocardial depression involves a complex mix of systemic (hemodynamic) factors and genetic, molecular, metabolic, and structural alterations. Pulmonary artery catheterization and modern echo-Doppler techniques are important diagnostic tools in this setting. There are no specific therapies for septic myocardial depression, and the cornerstone of management is control of the underlying infectious process (adequate antibiotic therapy, removal of the source) and hemodynamic stabilization (fluids, vasopressor and inotropic agents). In this review, we will summarize the pathogenesis, diagnosis, and treatment of myocardial depression in sepsis. Additional studies are needed in order to improve diagnosis and identify therapeutic targets in septic myocardial dysfunction
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