1,721,031 research outputs found
Pathophysiology of severe pulmonary hypertension in the critically ill patient
No full textPulmonary hypertension (PH) is a threatening condition that can be associated with a great variety of both pulmonary and extrapulmonary diseases. In all forms of severe PH the pulmonary vascular bed looses its physiological features of a "high flow-low pressure system", putting an increased afterload on the right ventricle (RV). Acute pulmonary hypertension in the intensive care unit often represents a clinical problem secondary to acute respiratory failure, left heart failure, pulmonary embolism, or decompensation of prior PH by concurrent pulmonary or cardiovascular disease. Right ventricular failure (acute cor pulmonale) occurs when relevant increases in pulmonary vascular resistance overwhelm its compensatory mechanisms, both abruptly on a previously normal RV, or gradually on a chronic cor pulmonale. This review addresses the main pathophysiolocal aspects of severe PH, focusing on the hemodynamic derangements occurring in the setting of acute cor pulmonale, and emphasizing the role of ventricular interdependance (the way right ventricular failure greatly affects diastolic and systolic function of the left ventricle), the risk of RV ischemia (the end stage of RV failure) and systemic organ hypoperfusion (caused by antegrade and retrograde heart failure). The understanding of the peculiar features of this type of cardiovascular insufficiency is necessary to both provide effective monitoring and adequate supportive therapy
Echocardiographic assessment of cardiovascular failure.
No full textIn the last few years echocardiography has gained an increasing role in critical care settings as invaluable tool for hemodynamic assessment of the unstable patient, due to its unique features of dynamic bedside imaging technique which can yield both morphologic and functional information. The main characteristics of cardiovascular function can be thoroughly explored, and a practical clinically-oriented approach can lead to answer the crucial questions of patient management, integrating (and often substituting) invasive monitoring, and allowing invasive monitoring pitfalls correction. Therapeutic impact of transesophageal echocardiography (TEE) has proven to be substantial in intensive care unit (ICU) population, although large randomized controlled studies are currently missing. Echocardiography requires specific training, but short training focused on the key hemodynamic information obtained from the shocked patient is proving to be effective. Echocardiographic hemodynamic evaluation should become part of routine assessment in the ICU soon, and critical care teams could achieve a hierarchic organization with respect to echocardiographic skills, with all members being at least able to perform a basic ultrasound examination of the heart, and a fewer who have gone through higher level formal training and board certification
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
What's new in ultrasound-based assessment of organ perfusion in the critically ill: expanding the bedside clinical monitoring window for hypoperfusion in shock
No full textVariations 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
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