Lung
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Noninvasive positive pressure ventilation (NPPV) has reemerged as an effective strategy for reducing morbidity and mortality associated with acute exacerbations of chronic obstructive pulmonary disease (COPD). During acute respiratory failure, dynamic hyperinflation, intrinsic PEEP, and increased airway resistance result in a mechanical workload that exceeds inspiratory muscle capacity. NPPV provides augmentation of alveolar ventilation and respiratory muscle rest. ⋯ NPPV performs better in COPD patients without significant comorbid illness. It should be initiated during COPD exacerbations if arterial pH is less than 7.35 or if the patient is severely distressed. Pressure support ventilation (10-20 cmH2O) via face mask is likely the optimal technique and, when successful, results in rapid clinical improvement.
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The symptom of breathlessness is an important outcome measure in the management of patients with chronic obstructive pulmonary disease (COPD). Clinical ratings of dyspnea and routine lung function are weakly related to each other. However, in the clinical setting breathlessness in COPD is encountered under conditions of increased respiratory effort, impeded respiratory muscle action, or functional weakness. ⋯ Our results demonstrate that the level of chronic exertional dyspnea in COPD increases as the ventilatory muscle derangement increases. The level of the relationships among dyspnea ratings and MVV and respiratory effort helps to explain some of the mechanisms of chronic dyspnea of COPD. These measures should be considered for therapeutic intervention to reduce dyspnea.