Clinics in chest medicine
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Clinics in chest medicine · Jun 2008
ReviewDoes closed loop control of assist control ventilation reduce ventilator-induced lung injury?
The standard of care for mechanical ventilation of the patient who has acute lung injury remains volume control ventilation at 6 mL/kg. Despite this fact, clinicians often employ pressure control ventilation and adaptive pressure control ventilation in an attempt to improve synchrony and limit the possibility for overdistension. ⋯ Neither of these techniques has been compared with volume control in a randomized setting. Understanding operation of these techniques is essential for determining any impact on outcome or ventilator induced lung injury.
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Clinics in chest medicine · Jun 2008
Review Comparative StudyProtocol-driven ventilator weaning: reviewing the evidence.
Though seminal clinical trials have identified efficacious methods of liberating patients from mechanical ventilation (ie, weaning), this knowledge is not applied often by physicians in routine practice. Weaning protocols are a strategies by which research results can be translated effectively and efficiently into clinical practice, but results of clinical trials evaluating weaning protocols have not been uniform, and controversy continues to surround this important area in critical care medicine. This article reviews the rationale for and against the routine use of weaning protocols and highlights informative details of many clinical trials that have evaluated such protocols.
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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.