American journal of respiratory and critical care medicine
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Am. J. Respir. Crit. Care Med. · Dec 2011
Randomized Controlled TrialEvolution of dyspnea during exercise in chronic obstructive pulmonary disease: impact of critical volume constraints.
Patients with chronic obstructive pulmonary disease (COPD) primarily describe their exertional dyspnea using descriptors alluding to increased effort or work of breathing and unsatisfied inspiration or inspiratory difficulty. ⋯ Regardless of the exercise test protocol, the inflection (or plateau) in the Vt response marked the point where dyspnea intensity rose abruptly and there was a transition in the dominant qualitative descriptor choice from "work and effort" to "unsatisfied inspiration." Intensity and quality of dyspnea evolve separately and are strongly influenced by mechanical constraints on Vt expansion during exercise in COPD.
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Am. J. Respir. Crit. Care Med. · Dec 2011
Randomized Controlled Trial Multicenter StudyImpact of race on asthma treatment failures in the asthma clinical research network.
Recent studies suggest that people with asthma of different racial backgrounds may respond differently to various therapies. ⋯ Despite having fewer asthma symptoms and less rescue β-agonist use, African-Americans with asthma have more treatment failures compared with whites, especially when taking long-acting β-agonists.