1,721,031 research outputs found
A Physiological Point of View on Expiratory (Re)action during Mechanical Ventilation
No full textA commonly held belief about avoiding ventilator-induced lung injury primarily takes into account the inflation half-cycle, whereas deflation is considered to be a passive process about which very little can be done to influence the lung function of patients (1). Is this belief actually correct? We know that patients should be ventilated without harming the lung (so-called rotective lung ventilation) (2). This may be achieved by combining low VT with the correct
amount of positive end-expiratory pressure (PEEP) to minimize the mechanical load on the ventilated lung. However, mechanical ventilation is different from the physiological mechanism that mammals use for gas exchange, in which the inspiratory flow is obtained by the negative pressure generated by the inspiratory muscle. Expiration is often believed to be passive and determined by the elastic recoil pressure of the lung, as it is during physiological ventilation. Unfortunately, expiration is not an exclusively passive phenomenon. The diaphragm not only acts as an inspiratory muscle but also exerts a braking action aimed at slowing down the expiratory flow (3)
Prone the lung and keep it prone!
No full textProne positioning (PP) has been used for a long time as a rescue therapy for severe hypoxemia in patients with ARDS because of its effectiveness in improving oxygenation and in reducing mortality in those with a more compromised Pao2 to Fio2 ratio (ie, < 150 mm Hg).1 Nevertheless, despite that the clinical indication for PP is to improve gas exchange, its benefits on mortality may be related to its veiled effects on stress and strain distribution, lung concentration of proinflammatory cytokines,2,3 and aeration and ventilation distribution throughout the lung.4,5 To sum up, its potential effects reduce the risk of ventilator-induced lung injury
Fatigue of ICU Survivors, No Longer to Be Neglected
No full textIn the last decades, the world of critical care is becoming increasingly focused not only on survival rates, but also on the well-being of critical care survivors. ARDS continues to represent an important public health problem despite an improvement in survival of approximately 60%.1-3 The long-lasting impairment after ARDS has been suggested as a more meaningful outcome measure than mortality.4 Accordingly, the research has focused on the postcritical sequelae that include physical, psychological, and emotional aspects. Patients who survive ARDS are at risk for physical dysfunction, neurocognitive disorders, and worsened quality of life 6 to 12 months after discharge from the ICU
Successful nasal intubation with a laryngeal nerve monitoring tube using bronchoscopy in a patient with plunging goiter: A case report
No full textBackground: The appropriate positioning of nerve integrity monitoring during thyroid surgery is of relevance. In this case report we describe our experience with accurate placement of a nerve integrity monitoring endotracheal tube, obtained by fiberoptic control, in a patient with expected difficult airway management. Case presentation: We report the case of a 70-year-old obese woman scheduled for elective total thyroidectomy due to plunging intrathoracic goiter. The preoperative indirect laryngoscopy pointed out a massive bombè of the hypopharyngeal wall to the right and right vocal cord paralysis. The epiglottis was oedematous and the glottis could not be identified. On physical examination, the tongue was large, and a Mallampati’s score of 3 was determined. Hence, due to an expected difficult airway management, a nasal intubation with an electromyographic nerve integrity monitoring endotracheal tube trough fiberoptic bronchoscopy was successfully performed.
Conclusion: Our experience suggests that nasal intubation can be safely performed by using a nerve integrity monitoring tube with the help of fiberoptic bronchoscopy
A methodological approach for determination of maximal inspiratory pressure in patients undergoing invasive mechanical ventilation.
No full textBackground. Maximal inspiratory pressure (MIP) can help to evaluate inspiratory muscle strength. However its determination in ventilated patients is cumbersome and needs special equipment. We hypothesized that MIP could be obtained by using the expiratory hold knob of the ventilator. The aim of this study was to verify whether: 1) the end expiratory occlusion technique can be used for MIP determination; and 2) if this technique provides different results compared to those obtained by the traditional method of MIP calculation. Methods. We studied 23 consecutive patients undergoing mechanical ventilation for acute respiratory failure. The MIP was determined by two different methods, both based on occluding the airway for 20 seconds. This occlusion was obtained either by pressing the expiratory hold knob of the ventilator; or by detaching the patient from the ventilator circuit and using a noiseless pneumatic shutter placed on the inspiratory line of a two-way valve that allows expiration but prevents inspiration. Results. The average values of MIP obtained by using either the hold knob of the ventilator or the noiseless pneumatic shutter were -46±14 cmH2O and -56±13 cmH2O, respectively. The linear regression analysis showed a significant correlation between MIPVent and MIPOcc (r2=0.95), although the Bland- Altman analysis revealed that they are not clinically comparable. Conclusion. MIP can be easily determined at the bedside by pressing the expiratory hold knob of ventilator. However, MIPVent and MIPOcc are different in terms of absolute value probably because they were determined at diverse lung volum
The Underestimated Role of Platelets in Severe Infection a Narrative Review
No full textBeyond their role in hemostasis, platelets have emerged as key contributors in the immune response; accordingly, the occurrence of thrombocytopenia during sepsis/septic shock is a well-known risk factor of mortality and a marker of disease severity. Recently, some studies elucidated that the response of platelets to infections goes beyond a simple fall in platelets count; indeed, sepsis-induced thrombocytopenia can be associated with—or even anticipated by—several changes, including an altered morphological pattern, receptor expression and aggregation. Of note, alterations in platelet function and morphology can occur even with a normal platelet count and can modify, depending on the nature of the pathogen, the pattern of host response and the severity of the infection. The purpose of this review is to give an overview on the pathophysiological interaction between platelets and pathogens, as well as the clinical consequences of platelet dysregulation. Furthermore, we try to clarify how understanding the nature of platelet dysregulation may help to optimize the therapeutic approach
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
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