1,720,956 research outputs found
Neurorespiratory drive output measurement in tetraplegic postraumatic patients (Mouth occlusion pressure at 100msec.: Pm 0.1)
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Time recovery course of maximum inspiratory and expiratory pressures in patients with spinal cord injury (lower cervical tract)
No full textAim of the Study: In quadriplegic patients with injuries below C5 segment of the cervical cord, the intercostal and abdominal muscles are paralysed so that ventilation is almost totally supported by diaphragm. We undertook this study in order to evaluate the degree of improvement of the respiratory muscles performance in quadriplegics patients admitted to an intensive rehabilitation program after the acute phase of injury.
Methods: We have enrolled 10 males and 1 female, mean age 46 years, with a cervical lesion C5-C7. All patients were tracheostomized and spontaneous ventilating via a tracheostomy tube. Both maximum inspiratory and expiratory pressures (Pimax, Pemax) were measured at admission and at the time when the patients seemed to be able to produce cough by themselves effectively with a standard procedure (the best pressure value of three consecutive inspiratory and expiratory efforts).
Results: The mean baseline values were Pimax 26 (SD 4.7) cmH2O Pemax 21.4 (SD 5.2) cmH2O increasing to 38.4 (SD 7.6) and 29.3 (SD 4.3) cmH20 respectively in presence of an effective cough. The mean elapsed time between the first and the second respiratory muscles force measurement was 118 days.
Conclusions: The major findings of this study are that respiratory muscles function improves in quadriplegic patients and moreover that a long period of time is necessary to elapse in order to ameliorate pulmonary function by increasing muscle force. Such gains in respiratory performance may be related to retraining of the deconditioned muscles, and to a better recruitment of accessory muscles of ventilation
Flow resistive properties of tracheostomy tubes and impact of external work of breathing in respiratory rehabilitation after traumatic brain injury
No full textBackground: The tracheostomy is, usually, performed in order to facilitate the suctioning of bronchial secretions so preventing atelectasis, pneumonia and increased V/Q mismatching. Nevertheless, the presence of a tracheostomy tube determines an extra burden for the respiratory muscle that could be crucial in order to maintain an adequate spontaneous ventilation. Therefore, we undertook this study to measure the impact of tracheostomy tubes on resistive external work of breathing.
Method: We measured, in vitro, the resistive properties of tracheostomy tubes (Shiley-Mallinkrodt Medical Italy), size 8-6 (internal diameter 7,6 mm and 6,4mm, length 81 and 78 mm, respectively), fenestrated and normally manufactured. We connected each cannula to the ‘Y’ piece of the inspiratory limb of the respiratory circuit and measured for each tube, different in size and characteristics, the drop in pressure, using the pressure transducer and pneumotacograph of the ventilator, along flow axis at different constant flow (0.5-1.0-1.2 L/s). By dividing the drop in pressure by the relative constant flow, we obtained the flow resistance (R) (cm H2O/L/s).
Results:
8 normal 8 fenestrated
Flow (L/s) R (cmH2O/L/s) Flow (L/s) R (cmH2O/L/s)
0.5 1.5 0.5 0.75
1.0 3.82 1.0 3.15
1.2 5.0 1.2 4.12
6 normal 6 fenestrated
Flow (L/s) R (cmH2O/L/s) Flow (L/s) R (cmH2O/L/s)
0.5 2.85 0.5 2.45
1.0 9.45 1.0 8.25
1.2 11.2 1.2 10.0
Conclusion: We can conclude that at high flow (1.0-1.2) Pres (R•Flow) (resistive pressure) is substantial, particularly with tubes of small size and the pressure the respiratory muscles have to generate to overcome the flow resistance offered by the tracheostomy tubes is higher in normally manufactured tubes than in fenestrated tubes with the same internal diameter; consequently external work performed by the patient is enhanced. This conclusion is very important in pulmonary rehabilitation treatment, during acute phase when there are TBI patients with tracheotomy and placement of a tracheotomy tube
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
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