Current opinion in critical care
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Curr Opin Crit Care · Feb 2008
ReviewStatic pressure-volume curves of the respiratory system: were they just a passing fad?
The aim of this article is to describe the physiologic utility, correlation with lung morphology, difficulties in interpretation and current clinical applications of static respiratory system pressure-volume curves at the bedside in patients with acute lung injury or acute respiratory distress syndrome. ⋯ The physiologic data obtained by measuring the static pressure-volume curves have helped clinicians to better understand the behavior of the respiratory system when positive-pressure ventilation is applied. The advanced technology incorporated into modern ventilators allows routine measurement of pressure-volume curves under sedation without paralysis, with acceptable variability and no serious adverse effects.
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Curr Opin Crit Care · Feb 2008
ReviewExtracellular matrix and mechanical ventilation in healthy lungs: back to baro/volotrauma?
The extracellular matrix plays an important role in the biomechanical behaviour of the lung parenchyma. The matrix is composed of a three-dimensional fibre mesh filled with different macromolecules, including proteoglycans which have important functions in many lung pathophysiological processes, as they regulate tissue hydration, macromolecular structure and function, response to inflammatory agents, and tissue repair and remodelling. The aim of this review is to describe the role of mechanical ventilation on pulmonary extracellular matrix structure and function. ⋯ Tidal volume reduction to 6 ml/kg may be useful during mechanical ventilation of healthy lungs. The study of the extracellular matrix may be useful to better understand the pathophysiology of ventilator-induced lung injury in healthy and diseased lungs.
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Curr Opin Crit Care · Feb 2008
ReviewDo airway secretions play an underappreciated role in acute respiratory distress syndrome?
We review the evidence that airway secretions may have an underappreciated role in acute respiratory distress syndrome, contributing to physiologic disarrangements, ventilator dependence and perhaps to injury generation. As common manipulations of ventilator settings, position and fluid status have the potential to influence these problems, explorations into the secretion dynamics of acute lung injury may be fertile ground for developing therapeutic advances. ⋯ Capability of ventilation and positioning to mobilize secretions implies the potential for clearance or containment of inflammatory mediators and infection. Ventilatory and positional prescriptions could be designed to meet one of either conflicting targets. Additional experimental and clinical investigations are required before adopting these proposed therapeutic principles into practice.
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Curr Opin Crit Care · Feb 2008
ReviewThe endothelium in acute lung injury/acute respiratory distress syndrome.
Since pulmonary edema from increased endothelial permeability is the hallmark of acute lung injury, a frequently encountered entity in critical care medicine, the study of endothelial responses in this setting is crucial to the development of effective endothelial-targeted treatments. ⋯ Mechanistic studies have delivered several interventions, which are effective in preventing and treating experimental acute lung injury and have thus provided objectives for translational studies. Some of these modalities may evolve into clinically useful tools in the treatment of this devastating illness.
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Curr Opin Crit Care · Feb 2008
ReviewRole of open-lung biopsy in acute respiratory distress syndrome.
When classic examinations such as bronchoalveolar lavage are not contributory in the etiologic diagnosis of unresolving acute respiratory distress syndrome, surgical lung biopsy would appear to be useful to determine the specific cause, particularly infection or postaggressive fibrosis, which could benefit from an adapted treatment. ⋯ Surgical lung biopsy could be proposed for patients with unresolving acute respiratory distress syndrome after 7-10 days of evolution despite well-conducted initial treatment when the etiology of acute respiratory distress syndrome has not been confirmed or when the appearance of postaggressive fibrosis is suspected.