1,721,200 research outputs found
Novel approaches to minimize ventilator-induced lung injury
Full text linkPurpose of reviewTo discuss the mechanisms of ventilator-induced lung injury and the pro and cons of the different approaches proposed by literature to minimize its impact in patients with acute respiratory distress syndrome.Recent findingsMechanical ventilation is indispensable to manage respiratory failure. The evolution of knowledge of the physiological principles and of the clinical implementation of mechanical ventilation is characterized by the shift of interest from its capability to restore normal gas exchange' to its capability of causing further lung damage and multisystem organ failure.SummaryIf one of the essential teachings to young intensivists in the 1980s was to ensure mechanical ventilation restored being able to immediately drain a pneumothorax (barotrauma), nowadays priority we teach to young intensivists is to implement protective' ventilation to protect the lungs from the pulmonary and systemic effects of ventilator-induced lung injury (biotrauma). At the same time, priority of clinical research shifted from the search of optimal ventilator settings (best positive end-expiratory pressure) and to the evaluation of super-protective' ventilation that integrating partial or total extracorporeal support tries to minimize the use of mechanical ventilation
Preoperative care in emergency surgery
No full textBe prepared. Sir Robert Baden-Powell Introduction Surgical emergencies in the elderly concern mainly trauma, intra-abdominal and vascular surgery. Abdominal pain constitutes 10-15% of all complaints and the unspecific nature of initial symptoms often makes accurate diagnosis difficult. Radiological imaging is often employed in aiding diagnosis and delay in performing these investigations can impact on surgical outcomes. Delays can be attributed to unstable hemodynamic conditions, delayed presentation of the illness, lack of physical signs at first presentation and inability to obtain proper history. The overall morbidity seems to be reduced when surgery is performed within the first 24-48 hours, whilst delays are associated with complications and higher mortality rates (Ryan et al. 2015). Emergency surgery is more frequent in the elderly than in younger patients and emergency cases have higher morbidity and mortality compared to elective surgery. The increased prevalence of age-related disease and comorbidity contrasts with the ability to recover from the physiological challenges of surgery and anesthesia and, especially in the setting of emergency surgery, there may not be time for complete evaluation and correction of risk factors. Clear understanding of the importance of identifying priorities, adequate organization in care delivery and a team approach is the most valid key for ensuring the best achievable outcome. Care Priorities in Geriatric Emergencies Pre-existing conditions and/or severe anatomical injuries increase the risk of poor outcome in elderly patients. Triage is defined as the identification of the severity of injury, the degree of physiological derangement and allocation of treatment according to priorities meant to increase the maximum number of survivors. A priority-wise approach should be employed when dealing with geriatric emergencies in order to correct all life-threatening conditions and give immediate organ support when required. Airway Control During the classic Airway, Breathing, Circulation, Disability, Exposure (ABCDE) assessment it is important to bear in mind the increased risk of aspiration as elderly patients have reduced protective airway reflexes secondary to muscular and neural degenerative changes. Correction of Hypovolemia Hypovolemia is very common in elderly patients presented for emergency surgery, even in the absence of bleeding or shock (Table 11.1). The tolerance to hypovolemia is poor in this specific population mainly because of the decreased β-receptor responsiveness and inadequate increase of heart rate in response to low cardiac output
Influence of methodological quality on study conclusions [3] (multiple letters)
No full textno abstrac
Pathophysiology of prone positioning in the healthy lung and in ALI/ARDS.
No full textProne position was initially introduced in healthy anesthetized and paralyzed subjects for surgical specific reasons. Then, it was used during acute respiratory failure to improve gas exchange. The interest on prone position during ALI/ARDS progressively increased, even if the mechanisms leading to a respiratory improvement are not yet completely understood. In normal subjects, during anesthesia and paralysis, prone position determines a more homogeneous distribution of the gravitational gradient of alveolar inflation, a ventilation distributed towards the non dependent lung regions and a reverse of the gravitational distribution of regional perfusion, even if factors other than gravity are involved. Moreover, prone position causes, both in healthy subject and in obese patients, an improvement in oxygenation and in functional residual capacity without affecting respiratory system, lung and chest wall compliance. In ALI/ARDS patients, prone position lead to a reverse of the alveolar inflation and ventilation distribution, due to the reverse of hydrostatic pressure overlying lung parenchyma, the reverse of heart weight, and the changes in chest wall shape and mechanical properties. Little data are available for the modifications in regional lung perfusion. The possible mechanisms involved in oxygenation improvement during prone position in ALI/ARDS patients are: 1) increased lung volumes; 2) redistribution of lung perfusion; 3) recruitment of dorsal spaces with more homogeneous ventilation and perfusion distribution. From a clinical point of view, prone position seems to be a very promising treatment for ALI/ARDS, even if its use is not yet a standard clinical practice. We have recently finished a randomized-controlled trial in order to investigate the clinical impact of this procedure. In the preliminary phase of the study performed in 35 Italian Intensive Care Units, we studied, from 1996 to 1998, 73 patients with a PaO2/FiO2 of 123 +/- 42 and a SAPS (Simplified Acute Physiology Score) of 38 +/- 11. After the first hour of prone positioning, the PaO2/FiO2 ratio of 76% of the patients had increased by more than 20 mmHg (responder) with a mean increase of 78 +/- 53 mmHg. The proportion of responders increased to 85% after 6 hours of prone positioning. The incidence of maneuver-related complications and severe and life-threatening complications was extremely rare. The overall mortality at ICU discharge was 51% and the ICU stay was similar in survivors and non survivors (17.8 +/- 11.6 vs 17.8 +/- 11.4 days)
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
- …
