Poor perception of dyspnea following methacholine challenge test in patients with asthma.

Objective: To determine the proportion of asthma patients with a poor perception of dyspnea, correlating the level of that perception with the severity of acute bronchoconstriction, bronchial hyperresponsiveness, use of maintenance medication, and asthma control.

Methods: Uncontrolled clinical trial involving asthma patients treated at the Pulmonology Outpatient Clinic of the São Lucas Hospital, in Porto Alegre , Brazil. Methacholine challenge testing was performed using a five-breath dosimeter protocol.

The role of the FEF50%/0.5FVC ratio in the diagnosis of obstructive lung diseases.

Objective: To evaluate the contribution of a new coefficient, the FEF50%/0.5FVC ratio, obtained from the maximal expiratory flow-volume curve, to the diagnosis of obstructive lung disease (OLD); to test this coefficient in differentiating among patients considered normal, those with OLD and those with restrictive lung disease (RLD); and to determine cut-off points for each functional diagnosis, as well as the probability for each diagnosis based on individual values.

Methods: A prospective, cross-sectional study analyzing the pulmonary function of patients referred to the Porto Alegre Hospital de Clínicas, in Porto Alegre, Brazil, between January and December of 2003.