Objective: To investigate the effects of airway obstruction on albuterol-mediated variations in the resistive and elastic properties of the respiratory system of adult patients with asthma. Methods: This study comprised 24 healthy controls and 69 patients with asthma, all of whom were nonsmokers. The patients were divided into three groups according to the severity of airway obstruction (mild, moderate or severe). Each of the three groups was divided into two subgroups according to the bronchodilator response (BR): positive (BR+) or negative (BR−). These measurements were conducted before and after albuterol use (300 µg). Airway obstruction was determined by means of spirometry, and the resistive and elastic properties were determined by means of the forced oscillation technique. Results: The resistance at the intercept (R0) presented greater reductions in the groups with higher obstruction. This reduction was more evident in the BR+ subgroups than in the BR− subgroups (p < 0.02 and p < 0.03, respectively). There was a significant difference between the control group and the BR+ subgroup with severe obstruction (p < 0.002). The reductions in dynamic elastance (Edyn) were significantly greater in proportion to the degree of obstruction, in the BR− subgroups (p < 0.03), and in the BR+ subgroups (p < 0.003). The reductions in Edyn were significantly greater in the BR− subgroup with moderate obstruction (p < 0.008) and in the BR+ subgroup with severe obstruction (p < 0.0005) than in the control group. Conclusions: In patients with asthma, increased airway obstruction results in greater reductions in R0 and Edyn after albuterol use. These reductions are greater among BR+ patients than among BR− patients.

Keywords: Asthma; Bronchodilator agents; Respiratory mechanics; Spirometry; Albuterol.

Objective: To correlate tomographic findings with pulmonary function findings, as well as to compare chest X-ray findings with high-resolution computed tomography (HRCT) findings, in patients with silicosis. Methods: A cross-sectional study was conducted in 44 non-smoking patients without a history of tuberculosis. Chest X-ray findings were classified according to the International Labour Organization recommendations. Using a semiquantitative system, the following HRCT findings were measured: the full extent of pulmonary involvement; parenchymal opacities; and emphysema. Spirometry and forced oscillation were performed. Pulmonary volumes were evaluated using the helium dilution method, and diffusing capacity of the lung for carbon monoxide was assessed. Results: Of the 44 patients studied, 41 were male. The mean age was 48.4 years. There were 4 patients who were classified as category 0 based on X-ray findings and as category 1 based on HRCT findings. Using HRCT scans, we identified progressive massive fibrosis in 33 patients, compared with only 23 patients when X-rays were used. Opacity score was found to correlate most closely with airflow, DLCO and compliance. Emphysema score correlated inversely with volume, DLCO and airflow. In this sample of patients presenting a predominance of large opacities (75% of the individuals), the deterioration of pulmonary function was associated with the extent of structural changes. Conclusions: In the early detection of silicosis and the identification of progressive massive fibrosis, HRCT scans are superior to X-rays.

Keywords: Silicosis; Occupational diseases; Tomography, x-ray computed; Respiratory function tests.

Objective: To use the forced oscillation technique to evaluate asthma patients presenting positive bronchodilator responses (confirmed through spirometry) and compare the results with those obtained in healthy individuals. Methods: The study sample consisted of 53 non-smoking volunteers: 24 healthy subjects with no history of pulmonary disease and 29 asthmatics presenting positive bronchodilator response, as determined through analysis of spirometry findings. All of the subjects were submitted to forced oscillation technique and spirometry immediately before and 20 minutes after the administration of salbutamol spray (300 g). The parameters derived from the forced oscillation technique were total respiratory resistance, total respiratory reactance, resistance extrapolated to the y axis, the slope of resistance, and dynamic compliance. The parameters measured in the spirometry evaluation tests were forced expiratory volume in one second and forced vital capacity. Results: In the control group, bronchodilator use produced a significant alteration in the resistance extrapolated to the y axis (p < 0.001), although no significant differences were observed in the slope of resistance or in dynamic compliance. Analysis of the asthma patients revealed significant differences between the prebronchodilator and postbronchodilator values for all spirometry and forced oscillation technique parameters. Values of p < 0.001 were obtained for all comparisons between the two groups. Conclusion: The modifications provoked by use of the forced oscillation technique were in direct concordance with the pathophysiology of the bronchodilator response in asthma patients, indicating that the forced oscillation technique could be useful as a complement to spirometry in these patients.

Keywords: Asthma; Bronchial hyperreactivity; Spirometry/methods; Bronchial provocation tests; Forced expiratory volume/physiology; Oscillometry

Objective: To evaluate the resistance values obtained through the use of the forced oscillation technique in patients with varying degrees of airway obstruction resulting from silicosis. Methods: A total of 40 never-smoking volunteers were analyzed: 10 were healthy subjects with no history of pulmonary disease or silica exposure, and 30 had silicosis. The forced oscillation technique was used to examine the subjects, and spirometry was used as a reference in order to classify the obstruction by degree. This classification resulted in five groups: control (n = 10); normal exam, composed of individuals diagnosed clinically and radiologically with silicosis but presenting normal spirometry results (n = 7); mild obstruction (n = 10); moderate obstruction (n = 8); and severe obstruction (n = 5). Results: The reduction observed in the spirometric values corresponded to a significant increase in the total respiratory resistance (p < 0.001), as well as in airway resistance (p < 0.003). A significant reduction in ventilation homogeneity was also observed (p < 0.004). Conclusion: In individuals with silicosis, the additional respiratory resistance-related data obtained through the use of the forced oscillation technique can complement spirometric data. Therefore, the forced oscillation technique presents great potential for the analysis of such patients.

Keywords: Pneumoconiosis; Silicosis; Forced expiratory volume; Oscillometry; Respiratory function tests

Objective: To evaluate alterations in pulmonary function in patients with systemic sclerosis-associated interstitial pneumonia over a five-year period. Methods: This was a longitudinal study involving 35 nonsmoking patients with systemic sclerosis and without a history of lung disease. At the first evaluation, performed at the time of the diagnosis of interstitial pneumonia, the patients were submitted to HRCT, spirometry, and measurement of DLCO. The patients were subdivided into two groups by the presence or absence of honeycombing on the HRCT scans. Approximately five years after the first evaluation, the patients were submitted to spirometry and measurement of DLCO only. Results: Of the 35 patients, 34 were women. The mean age was 47.6 years. The mean time between the two evaluations was 60.9 months. Honeycombing was detected on the HRCT scans in 17 patients. In the sample as a whole, five years after the diagnosis, FVC, FEV1 and DLCO significantly decreased (81.3 ± 18.2% vs. 72.1 ± 22.2%; 79.9 ± 17.8% vs. 72.5 ± 20.6%; and 74.0 ± 20.5% vs. 60.7 ± 26.8%, respectively; p = 0.0001 for all), and the FEV1/FVC ratio significantly increased (98.5 ± 7.2% vs. 101.9 ± 7.8%; p = 0.008). In the same period, FVC, FEV1, and DLCO values were significantly lower in the patients with honeycombing on the HRCT scans than in those without (p = 0.0001). Conclusions: In systemic sclerosis-associated interstitial lung disease, the detection of honeycombing on HRCT is crucial to predicting accelerated worsening of pulmonary function.

Keywords: Scleroderma, systemic; Respiratory function tests; Tomography, X-ray computed.

Objective: To correlate tomographic findings with pulmonary function parameters in patients with idiopathic pulmonary fibrosis (IPF). Methods: A cross-sectional study was carried out, in which 30 nonsmoking patients with IPF were evaluated. Using a semiquantitative scoring system, the following high-resolution computerized tomography (HRCT) findings were quantified: total interstitial disease (TID), reticular abnormality/honeycombing, and ground-glass opacity (GGO). The functional variables were measured by spirometry, forced oscillation technique (FOT), helium dilution method, as well as the single-breath method of measuring diffusion capacity of the lung for carbon monoxide (DLCO). Results: Of the 30 patients studied, 18 were female, and 12 were male, with a mean age of 70.9 years. We found that TID and reticular abnormality and honeycombing correlated significantly (negative correlations) with the measurements of forced vital capacity (FVC), total lung capacity (TLC), DLCO, and dynamic respiratory compliance were found, as well as that GGO correlated significantly (and positively) with residual volume/TLC. The ratio of forced expiratory flow between 25 and 75% of FVC to FVC (FEF25-75%/FVC) correlated positively with TID, reticular abnormality/honeycombing, and GGO. Conclusion: In IPF patients, the measurements of volume, diffusion, and dynamic compliance are the physiological variables which best reflect the extent of the interstitial disease on HRCT scans.

Keywords: Lung diseases, interstitial; Pulmonary fibrosis; Tomography, X-ray computed; Respiratory function tests.

Microsporidiosis is a rapidly emerging protozoon infection that has been reported predominantly in severely immunosuppressed persons with acquired immunodeficiency syndrome (AIDS). Since the first case of human microsporidian infection was reported in 1956, over 400 cases have been documented. The initial description of microsporidian infection in AIDS patients occurred in 1985. Five genera have been identified as the agents of microsporidiosis in immunocompromised persons (Enterocytozoon, Encephalitozoon, Septata, Pleistophora and Nosema). Respiratory tract infection due to microsporidia is associated almost exclusively with disseminated disease produced by members of the genera Encephalitozoon and Septata. Metronidazole and albendazole were recently reported to be responsible for clinical improvement of patients. The authors reported a case of a woman with AIDS and respiratory symptoms related to two pulmonary pathogens: Mycobacterium tuberculosis and Encephalitozoon cuniculi, identified by polymerase chain reaction (PCR) using diagnostic primers targeting the small subunit ribosomal RNA.

Keywords: Microsporidiosis. Respiratory tract infection. Acquired immunodeficiency syndrome.

Behçet's disease is a systemic disease with clinical manifestations, whose underlying histopathologic lesion is a non-specific vasculitis. Pulmonary artery aneurysms and, more rarely, pleuropulmonary manifestations may be found. Some reports are available in the literature about the use of immunosuppressive agents in these conditions. The authors describe a case in whom clinical remission and radiologic resolution were observed after corticosteroid and cyclophophamide therapy.

Keywords: Behçet's disease. Pulmonary artery aneurysms.

Primary pulmonary hypertension (PPH) is a disease of rare, unclear etiology, leading to elevations in pulmonary artery pressure and pulmonary vascular resistance. The vascular lesions range from mild - consisting of neo-intimal proliferation - to severe - characterized by concentric intimal fibrosis, plexiform lesions, and necrotizing arteritis. There have been since 1987 reports describing the association between human immunodeficiency virus (HIV) and PPH, with as many as 60 patients in 1997. The role of HIV in the pathogenesis remains unclear. It is reported a case of a woman in whom this association was observed.

Keywords: Primary pulmonary hypertension. Human immunodeficiency virus.

Objective: Current debates on the bronchodilator response in COPD patients and whether the variation in FEV1 can be considered as an indicator of complete reversibility in such patients motivated us to conduct this study. The objective of the study was to determine the effect of albuterol on the resistive and reactive properties of the respiratory system in COPD patients. Methods: We evaluated 70 patients with COPD, divided into two groups based on spirometry findings: bronchodilator (BD)-negative (n = 39); and BD-positive (n = 31). We used the forced oscillation technique (FOT) to evaluate the following parameters: resistance at the intercept (R0), associated with the total resistance of the respiratory system; mean resistance (Rm), associated with central airway resistance; dynamic compliance (Cdyn); and the slope of resistance (S) and mean reactance (Xm), both of which are associated with the homogeneity of the respiratory system. Results: The use of albuterol resulted in significant reductions in R0 (p < 0.00002) and Rm (p < 0.0002). There were also significant increases in S (p < 0.0001), Cdyn (p < 0.0001) and Xm (p < 0.00004). These modifications occurred in both groups, the changes in FOT parameters being greater than those observed for spirometric parameters. Conclusions: The use of albuterol improved the resistive and reactive properties of the respiratory system of the COPD patients under study. These changes occurred regardless of the FEV1-based classification, thereby indicating that the use of this parameter in isolation might not suffice to identify the physiological effects involved.

Keywords: Pulmonary disease, chronic obstructive; Bronchodilator agents; Spirometry; Albuterol.

Objective: To evaluate inspiratory volume in patients undergoing cardiac surgery and to determine the effects that incentive spirometry (IS) and the breath stacking (BS) technique have on the recovery of FVC in such patients. Methods: A prospective, controlled, randomized clinical trial involving 35 patients undergoing cardiac surgery at the Hospital de Força Aérea do Galeão (HFAG, Galeão Air Force Hospital), in the city of Rio de Janeiro, Brazil. The patients, all of whom performed mobilization and cough procedures, were randomly divided into three groups: exercise control (EC), performing only the abovementioned procedures; IS, performing the abovementioned procedures and instructed to take long breaths using an incentive spirometer; and BS, performing the abovementioned procedures, together with successive inspiratory efforts using a facial mask coupled to a unidirectional valve. Forced spirometry was carried out in the preoperative period and on postoperative days 1 to 5. During the maneuvers, inspiratory volume was measured in the IS and BS groups. Results: On postoperative day 1, FVC significantly decreased in all groups (EC: 87.1 vs. 32.0%; IS: 75.3 vs. 29.5%; and BS: 81.9 vs. 33.2%; p < 0.001 for all), as did inspiratory volume in the IS and BS groups (2.29 vs. 0.82 L; and 2.56 vs. 1.34 L, respectively; p < 0.001 for both). Between postoperative days 1 and 5, FVC partially normalized in all groups (EC: 32.0 vs. 51.3%; IS: 29.5 vs. 46.7%; and BS: 33.3 vs. 54.3%; p < 0.001 for all). During the postoperative period, inspiratory volume was significantly higher in the BS group than in the IS group. Conclusions: The three protocols were equivalent concerning the recovery of FVC on the first five postoperative days. When compared with IS, the BS technique promoted higher inspiratory volumes in this sample of postoperative cardiac patients. (ClinicalTrials.gov Identifier:NCT01074957 [http://www.clinicaltrials.gov/])

Keywords: Postoperative complications; Thoracic surgery; Physical therapy modalities.