1,720,992 research outputs found
Patient-ventilator interaction and inspiratory effort during pressure support ventilation in patients with different pathologies.
No full textThe aim of this study was to evaluate whether pressure support ventilation (PSV) requires different diaphragmatic efforts and patient-ventilator matching, according to the underlying disease. Four groups of patients requiring PSV were studied: Group A, recovering from an episode of acute respiratory failure due to adult respiratory distress syndrome (ARDS); Group B, with postsurgical complications; and two subsets of chronic obstructive pulmonary disease (COPD) patients, with "normal" static compliance of the respiratory system (Cst,rs) (Group C) or elevated Cst,rs (Group D). Ventilatory pattern, transdiaphragmatic pressure (Pdi), the pressure-time product of the diaphragm (PTPdi), static (PEEPi,stat) and dynamic intrinsic positive end-expiratory pressure (PEEPi,dyn), Cst,rs and resistance of the total respiratory system (Rrs) were recorded. The matching between patient and ventilator was analysed, recording the number of "ineffective efforts" (inspiratory efforts not efficient enough to trigger a new ventilator cycle, despite a positive deflection in Pdi). A satisfactory blood gas equilibrium arterial oxygen saturation (Sa,O2 > 93\%, with a pH > 7.32) was obtained in the various groups with different levels of PSV. Minute ventilation was found to be significantly higher in Groups A and B, due to the longer expiratory time (tE) in the COPD groups. Group A (2 out of 7), Group B (3 out of 7), Group C (3 out of 5) patients showed sporadic "ineffective efforts". All Group D patients manifested continuous mismatching with the ventilator, so that the pressure-time product of the diaphragm per minute (PTPdi/min), reflecting the metabolic work of the diaphragm, was not different in the four groups. Tidal volume and the spontaneous inspiratory efforts were similar in the four groups, but the number of breaths delivered by the ventilator was significantly higher in Groups A and B. The application of different levels of pressure support ventilation in patients with acute respiratory failure due to different pathologies, led them to breathe with comparable pressure time product of the diaphragm. The majority of the patients showed mismatching with the ventilator, although this effect was more pronounced in the groups with chronic obstructive pulmonary disease
Insufficienza respiratoria cronica ipercapnica in paziente con rigetto cronico polmonare
No full textLung transplantation: the new point of view of an italian centre
No full textLung transplantation has become an accepted therapy for patients with end-stage lung disease. The survival rate after this operation is not, however, satisfactory, being 40-50% at 5 yrs after lung transplantation; infections and pulmonary rejection (acute and chronic) are the cause of this brief survival. Recently, it has been shown that lung transplantation is an advantageous solution only for selected pathologies. The introduction of alternatives to lung transplantation (lung volume reduction surgery in emphysema, prostacyclin therapy in primary pulmonary hypertension and pulmonary thromboendarterectomy in chronic thromboembolic hypertension) has modified the number of patients admitted to the lung transplantation waiting list. In this study, admission to the lung transplantation waiting list in the first 50 and in the following 50 months of activity of the Pulmonary Division Medical Centre of Montescano were retrospectively compared in order to verify whether experience gained has influenced admission to the lung transplantation waiting list. The mortality rate of patients with idiopathic pulmonary fibrosis (44%), chronic thromboembolic pulmonary hypertension (50%) and primary pulmonary hypertension (52%) before lung transplantation was high; the mortality after lung transplantation was low in idiopathic pulmonary fibrosis (16%), but rather high in primary pulmonary hypertension (55%) and chronic thromboembolic pulmonary hypertension (50%). In contrast, the mortality rate of patients with Eisenmenger's syndrome and emphysema was fairly low while on the lung transplantation waiting list, but rather high after lung transplantation. The trend in admission to the lung transplantation waiting list changed during the two observation periods, with a reduction in the number of patients with Eisenmenger's syndrome and emphysema, but not of those with idiopathic pulmonary fibrosis, chronic thromboembolic pulmonary hypertension and primary pulmonary hypertension. The experience gained modified the authors' approach to lung transplantation, but the "world" of lung transplantation still needs a lot more experience
Insufficienza respiratoria cronica ipercapnica in paziente con rigetto cronico polmonare: è utile la ventiloterapia invasiva quando la non invasiva fallisce?
No full textSindrome di Eisenmenger e criteri di ammissione alle liste d'attesa per trapianto polmonare
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
- …
