Clinics in chest medicine
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Clinics in chest medicine · Jun 2008
ReviewDo newer monitors of exhaled gases, mechanics, and esophageal pressure add value?
The current understanding of lung mechanics and ventilator-induced lung injury suggests that patients who have acute respiratory distress syndrome should be ventilated in such a way as to minimize alveolar over-distension and repeated alveolar collapse. Clinical trials have used such lung protective strategies and shown a reduction in mortality; however, there is data that these "one-size fits all" strategies do not work equally well in all patients. This article reviews other methods that may prove useful in monitoring for potential lung injury: exhaled breath condensate, pressure-volume curves, and esophageal manometry. The authors explore the concepts, benefits, difficulties, and relevant clinical trials of each.
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Clinics in chest medicine · Jun 2008
ReviewCurrent role of high frequency oscillatory ventilation and airway pressure release ventilation in acute lung injury and acute respiratory distress syndrome.
Lung protective ventilatory strategies using conventional ventilators have resulted in decreased mortality in adult patients who have acute lung injury and acute respiratory distress syndrome. Conceptually, high frequency oscillatory ventilation and airway pressure release ventilation appear not only able to fulfill the goals of lung protection, but also to offer some additional advantages over conventional ventilation. Although early data for each of these modes in adults have been encouraging, their widespread use--particularly outside of a rescue situation--cannot be recommended without further evidence.
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Clinics in chest medicine · Jun 2008
ReviewProportional assist ventilation and neurally adjusted ventilatory assist--better approaches to patient ventilator synchrony?
Understanding the regulation of breathing in the critical care patient is multifaceted, especially in ventilator-dependent patients who must interact with artificial respiration. Mechanical ventilation originally consisted of simple, manually-driven pump devices, but it has developed into advanced positive pressure ventilators for continuous support of patients in respiratory failure. ⋯ Recently, modes of mechanical ventilation that synchronize not only the timing, but also the level of assist to the patient's own effort, have been introduced. This article describes the concepts related to proportional assist ventilation and neurally adjusted ventilatory assist, and how they relate to conventional modes in terms of patient-ventilator synchrony.
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Clinics in chest medicine · Jun 2008
ReviewIs there a best way to set positive expiratory-end pressure for mechanical ventilatory support in acute lung injury?
Airspace collapse is a hallmark of parenchymal lung injury. Strategies to reopen and maintain patency of these regions offer three advantages: improved gas exchange, less lung injury, and improved lung compliance. Elevations in intrathoracic pressure to achieve these goals, however, may overdistend healthier lung regions and compromise cardiac function. Positive expiratory-end pressure is a widely used technique to maintain alveolar patency, but its beneficial effects must be balanced against its harmful effects.
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With the increasing threat of pandemic influenza and catastrophic bioterrorism, it is important for intensive care providers to be prepared to meet the challenge of large-scale airborne epidemics causing mass casualty respiratory failure. The severe acute respiratory syndrome outbreak exposed the vulnerability of health care workers and highlighted the importance of establishing stringent infection control and crisis management protocols. ⋯ Controversy remains regarding the use of high-frequency oscillatory ventilation and noninvasive positive pressure ventilation. Standard, contact, and airborne precautions should be instituted in intensive care units, with special care taken when aerosol-generating procedures are performed.