1,721,276 research outputs found
Albumin in critically ill patients : the ideal colloid?
No full textFurther studies are needed to clarify physiology and clinical impact of albumin in critically ill patients, considering specific phenotypes and secondary outcomes other than survival, yet clinically relevant
Clinical review : Extracorporeal membrane oxygenation
Full text linkThe H1N1 fl u pandemic led to a wider use of
extracorporeal membrane oxygenation (ECMO),
proving its power in hypoxemic emergencies. The results obtained during this pandemic, more than any randomized trial, led to the worldwide acceptance of the use of membrane lungs. Moreover, as centers that applied this technique as rescue therapy for
refractory hypoxemia recognized its strength and limited technical challenges, the indications for ECMO have recently been extended. Indications for venovenous
ECMO currently include respiratory support
as a bridge to lung transplantation, correction of lung hyperinfl ation during chronic obstructive pulmonary disease exacerbation and respiratory support in
patients with the acute respiratory distress syndrome, possibly also without mechanical ventilation. The current enthusiasm for ECMO in its various aspects should not, however, obscure the consideration of the potential complications associated with this life-saving technique, primarily brain hemorrhage
Acute lung injury/acute respiratory distress syndrome pathophysiology : what we have learned from computed tomography scanning
No full textPURPOSE OF REVIEW: Although many years have passed since its first application in acute respiratory distress syndrome, computed tomography remains widely employed for research and clinical purposes. Here, we review recent findings derived from computed tomography scanning during acute respiratory distress syndrome, particularly concerning setting positive end-expiratory pressure and mechanisms of ventilator-induced lung injury. RECENT FINDINGS: Several studies have provided evidence for the validity of monitoring dynamic mechanics of the respiratory system to estimate the balance between beneficial (i.e. reduction of alveolar derecruitment) and harmful (i.e. lung hyperinflation) effects, consequent to positive end-expiratory pressure increase. The combination of different respiratory variables to estimate lung recruitment has become a more accepted approach. Computed tomography scanning has provided important evidence of lung hyperinflation even after the use of low tidal volume in a specific category of patients. Alternative techniques, such as electrical impedance tomography and lung ultrasound, appear as promising tools potentially available at the bedside. SUMMARY: As far as setting positive end-expiratory pressure is concerned, further randomized clinical studies are warranted to verify the pathophysiologic findings recently observed with computed tomography scanning. Similarly, the safety of the widespread use of low tidal volume should be brought into question, possibly pointing out a category of patients who may benefit from alternative techniques of respiratory support
Towards ultraprotective mechanical ventilation
No full textPurpose of review : To survey the causes of ventilator-induced lung injury focusing on its mechanical determinants, lung stress and strain. Recent findings : Tidal volume per ideal body weight (tidal volume/IBW) and airway pressure (PAW) are poor surrogates of strain and stress, which are respectively defined as the ratio of volume variation to lung resting volume and transpulmonary pressure. In healthy lungs, ventilation becomes lethal with strain reaching total lung capacity (tidal volume/IBW around 30-40 ml/kg) and with its related stress (roughly 24cmH2O). The striking discrepancy between experimental data and clinical scenarios (harm at tidal volume/IBW of 12 ml/kg) may be explained by lung dishomogeneity, locally generating 'stress risers' or 'pressure multipliers'. When mechanical ventilation becomes unsafe, as inferred from computed tomography-scan evaluation of dishomogeneity and stress/strain values, lung protective strategies can be maximized by further reducing tidal volume and increasing PAW (e.g. high frequency oscillatory ventilation). In alternative, artificial lungs may provide adequate gas exchange while reducing the load of mechanical ventilation. Recently, outcome benefit was shown with the use of this technique in H1N1 patients. Summary : When lung protective strategy is considered unsafe, various techniques of extracorporeal respiratory support may be applied, which by decreasing the load of mechanical ventilation, allow partial to total lung rest
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
Pathophysiology and therapeutic strategy of respiratory alkalosis
No full textRespiratory alkalosis is a condition characterized by low partial pressure of carbon dioxide and an associated elevation in arterial pH caused by an imbalance between CO2 production and removal, in favour of the latter. Conditions that cause increased alveolar ventilation, without having a reduction in pH as input stimulus, will cause hypocapnia associated with a variable degree of alkalosis. The major effect of hypocapnia is the increase in pH (alkalosis) and the consequent shift of electrolytes that occurs in relation to it. As a general law, in plasma, anions will increase, while cations will decrease. The acute reduction in ionized calcium, due to the change in extracellular pH, may cause neuromuscular symptoms ranging from paraesthesias, to tetany and seizures. The effect on urine is an increase in urinary strong ion difference/urinary anion gap and a consequent increase in urinary pH. Finally, acute hypocapnic alkalosis causes a constriction of cerebral arteries that can lead to a reduction of cerebral blood flow. The clinical approach to respiratory alkalosis is usually directed toward the diagnosis and treatment of the underlying clinical disorder
Urinary electrolyte monitoring in the critically ill: revisiting renal physiology
No full textThe kidney, being one of the most fascinating and commonly studied organs within human physiology, has a crucial role in maintaining the homeostasis of our organism from several different perspectives, from clearing of cellular catabolism products, to body fluids and electrolyte content regulation, hemodynamic stability and acid-base equilibrium [1]. Consequently, despite the existence of many strategies to support its function, the renal system is often the focus of our attention during the clinical management of the critically ill, because its function is frequently altered in this category of patient
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