Objective: To determine whether the results of pulmonary function tests carried out in patients subsequently submitted to hematopoietic stem cell transplantation (HSCT) are associated with post-HSCT mortality. Methods: This was a prospective study involving patients older than 15 years of age who were submitted to allogenic HSCT between January of 2007 and March of 2008 at the Hospital das Clínicas da Universidade Federal de Minas Gerais, located in the city of Belo Horizonte, Brazil. Prior to HSCT, all of the patients underwent spirometry, determination of lung volumes, and determination of DLCO. Those same tests were repeated six months, one year, and two years after HSCT. Kaplan-Meier curves and two-tailed log-rank tests were used for survival analysis. The relative risk (RR) and 95% CI were calculated using the Cox proportional hazards model. The Cox regression model was used in the multivariate analysis. Results: The pre-HSCT pulmonary function results were normal in 40 (74.1%) of the 54 patients evaluated, 19 (35.2%) of whom died within the first 100 days after HSCT. By the end of the two-year follow-up period, 23 patients (42.6%) had died, the most common causes of death being septicemia, observed in 11 (47.8%), and septicemia-related respiratory insufficiency, observed in 10 (43.4%). The only variables significantly associated with post-HSCT mortality were alterations in spirometry results prior to HSCT (RR = 3.2; p = 0.016) and unrelated donor (RR = 9.0; p < 0.001). Conclusions: Performing spirometry prior to HSCT provides baseline values for future comparisons. Although alterations in spirometry results reveal a higher risk of post-HSCT mortality, such alterations do not contraindicate the procedure.

Keywords: Hematopoietic stem cell transplantation/mortality; Respiratory function tests; Donor selection.

Background: Spirometry is widely used in the diagnosis and quantification of respiratory disorders such as asthma. A microspirometer is a portable and easily used apparatus that can substitute for a regular spirometer, although there is little evidence of its accuracy. Objective: To compare the microspirometer to a regular spirometer for use in asthmatic children and adolescents. Methods: The instruments used were a Micro Spirometer, manufactured by Micro Medical, and a conventional Cosmed Pony Graphic 3.5 spirometer, both with turbinometers (flow sensors). The study sample consisted of 62 children and adolescents, of both genders, clinically diagnosed with asthma and under treatment at a pulmonology clinic. Ages ranged from 5 and 16 years. All spirometric tests were carried out according to the guidelines established by the American Thoracic Society and by the Associacão Brasileira de Normas Técnicas (Brazilian Technical Standards Association). For each patient, microspirometry was performed first, followed by conventional spirometry. The parameters analyzed in both devices were forced vital capacity, forced expiratory volume in one second and peak expiratory flow. Data were analyzed using the Student's t-test and Pearson's correlation test. Results: Strong correlations were found between the two devices in the parameters analyzed: forced expiratory volume in one second: r = 0.97; forced vital capacity: r = 0.97; and peak expiratory flow: r = 0.91. Conclusion: These results demonstrate that the microspirometer is a useful diagnostic tool that can be used when a conventional spirometer is unavailable.

Keywords: Key words: Asthma. Spirometry. Micro spirometer. Puomonary ventilation.

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 evaluate quality of sleep and pulmonary function in clinically stable adolescents with sickle cell anemia (SCA). Methods: A cross-sectional descriptive study involving 50 patients with SCA submitted to nocturnal polysomnography and spirometry at the Brasília University Hospital. Anthropometric, polysomnographic and pulmonary function data were analyzed. Patients were divided into two groups according to oxygen saturation by pulse oximetry (SpO2) during rapid eye movement (REM) sleep: SpO2 ≤ 93%; and SpO2 > 93%. Descriptive statistics, Student's t-test, chi-square test and Pearson's correlation coefficient were used. Results: Mean age was 13.9 ± 2.5 years. Total sleep time and REM sleep percentage were lower, whereas REM sleep latency, the number of awakenings, movement during sleep, changes in sleep stage, sleep-disordered breathing index and obstructive apnea index were higher. Two patients (4%) did not present REM. There were statistically significant differences between the groups in most of the polysomnographic variables. The SpO2 in REM sleep presented a strong positive correlation with waking SpO2 and with SpO2 in non-REM sleep, whereas it presented a strong negative correlation with the percentage of total sleep time during which SPO2 was < 90%. Mean spirometric values were within normal ranges. Residual volume and the residual volume/total lung capacity/functional residual capacity ratio were elevated. Conclusion: Sleep impairment in clinically stable patients with SCA is probably due to hemoglobin desaturation and not to individual alterations in pulmonary function.

Keywords: Sleep disorders; Polysomnography; Adolescent; Anemia, sickle cell; Spirometry.

Objective: To evaluate pulmonary function and functional capacity in children and adolescents with sickle cell disease. Methods: This was a cross-sectional study involving 70 children and adolescents (8-15 years of age) with sickle cell disease who underwent pulmonary function tests (spirometry) and functional capacity testing (six-minute walk test). The results of the pulmonary function tests were compared with variables related to the severity of sickle cell disease and history of asthma and of acute chest syndrome. Results: Of the 64 patients who underwent spirometry, 15 (23.4%) showed abnormal results: restrictive lung disease, in 8 (12.5%); and obstructive lung disease, in 7 (10.9%). Of the 69 patients who underwent the six-minute walk test, 18 (26.1%) showed abnormal results regarding the six-minute walk distance as a percentage of the predicted value for age, and there was a ≥ 3% decrease in SpO2 in 36 patients (52.2%). Abnormal pulmonary function was not significantly associated with any of the other variables studied, except for hypoxemia and restrictive lung disease. Conclusions: In this sample of children and adolescents with sickle cell disease, there was a significant prevalence of abnormal pulmonary function. The high prevalence of respiratory disorders suggests the need for a closer look at the lung function of this population, in childhood and thereafter.

Keywords: Anemia, sickle cell; Respiratory function tests; Exercise test.

Introduction: Spirometry and analysis of blood gases data have been extensively used to assess ventilatory limitation and prognosis of COPD patients. However, functional physical tests, such as the six-minute walk test (6wt) have been used for the dynamic assessment of COPD patients. Objective: To determine correlations between respiratory function test data and the six-minute walk test in COPD patients. Patients and methods: 45 patients were submitted to clinical history survey and complete physical examination performed by the medical staff of the Pneumology Department of the Brasilia University Hospital, followed by spirometry, analysis of arterial blood gases, maximal respiratory pressures data, and the six-minute walk test. Results: Concerning the spirometric, analysis of blood gases and maximal respiratory pressures data, statistically significant positive correlations (p < 0.05) between FEV1, PaO2, SpO2, MEP and the six-minute walk test were obtained. Conclusions: For the studied group, the six minute walk test has significant correlation with FEV1, PaO2, SpO2 and MEP, and can be used as an alternative functional assessment of COPD patients.

Objective: To describe the pulmonary function in children and adolescents with postinfectious bronchiolitis oblite­rans (PIBO), as well as to evaluate potential risk factors for severe impairment of pulmonary function. Methods: The pulmonary function of 77 participants, aged 8-18 years, was assessed by spirometry and plethysmography. The following parameters were analyzed: FVC; FEV1; FEF25-75%; FEV1/FVC; RV; TLC; RV/TLC; intrathoracic gas volume; and specific airway resistance (sRaw). We used Poisson regression to investigate the following potential risk factors for severe impairment of pulmonary function: gender; age at first wheeze; age at diagnosis; family history of asthma; tobacco smoke exposure; length of hospital stay; and duration of mechanical ventilation. Results: The mean age was 13.5 years. There were pronounced decreases in FEV1 and FEF25-75%, as well as increases in RV and sRaw. These alterations are characteristic of obstructive airway disease. For the parameters that were the most affected, the mean values (percentage of predicted) were as follows: FEV1 = 45.9%; FEF25-75% = 21.5%; RV = 281.1%; RV/TLC = 236.2%; and sRaw = 665.3%. None of the potential risk factors studied showed a significant association with severely impaired pulmonary function. Conclusions: The patients with PIBO had a common pattern of severe pulmonary function impairment, characterized by marked airway obstruction and pronounced increases in RV and sRaw. The combination of spirometric and plethysmographic measurements can be more useful for assessing functional damage, as well as in the follow-up of these patients, than are either of these techniques used in isolation. Known risk factors for respiratory diseases do not seem to be associated with severely impaired pulmonary function in PIBO.

Keywords: Respiratory function tests; Airway obstruction; Bronchiolitis obliterans

Objective: Asthma is the most common chronic pulmonary disease, characterized by bronchial inflammation. Some children with asthma have persistent pulmonary function impairment. The prevalence and etiology of this abnormality in children with asthma in developing countries remain unknown. The objective of this study was to estimate the proportion of patients with impaired pulmonary function who were unresponsive to treatment in a group of children and adolescents with asthma, and to describe the phenotypic characteristics of the sample. Methods: Using a standardized questionnaire, we selected outpatients (5-17 years of age) diagnosed with persistent asthma. These patients underwent spirometry and skin prick tests for sensitivity to common aeroallergens. Persistent pulmonary function impairment was defined as an FEV1/FVC ratio < 0.80, even after 10 days of treatment with bronchodilators and oral corticosteroids. We used the atopic index to differentiate between patients with little or no response to the skin prick test and those with a strong response (cut-off point: 4 allergens). Results: We included 96 patients with a mean age of 10.6 years. Of those, 52 (54.1%) were male, and 89 (92.7%) were atopic. Of the 96 patients, 8 (8.3%) had impaired pulmonary function even after the treatment. Among those patients, 8 (100%) were atopic, 7 (87.5%) had moderate or severe asthma, and 7 (87.5%) had a history of hospitalization for acute bronchiolitis. Conclusions: Children and adolescents with moderate or severe asthma can present with impaired pulmonary function and be unresponsive to treatment. This clinical situation has been little studied in developing countries, and its risk factors and etiology will be better understood only through birth cohort studies.

Keywords: Asthma; Respiratory function tests; Allergy and immunology.

Background: Obesity can effect the thorax, diphragm and abdominal muscles, thereby resulting in altered respiratory function. Objective: To evaluate the effects of obesity and to determine whether body mass index (BMI) and waist circumference correlate with spirometry values in obese individuals. Method: We studied 96 non-smokers of both sexes, 48 suffering from class I and class II obesity and ranging in age rom 18 to 75. All participants presented a BMI between 30 kg/m2 and 40 kg/m2 and none had a history of morbidity. Spirometry was performed, and waist circumferences were measured. Results: No significant differences were found between the spirometric values of men with class I or II obesity and those of non-obese men. In obese women, forced vital capacity and forced expiratory volume in one second (FEV1) were significantly lower than in women who were not obese. Obese individuals of both sexes presented significantly lower expiratory reserve volume (ERV) than did non-obese individuals. Although inspiratory capacity was greater in obese men and women, the difference was significant only for the men. In obese men, there was a significant negative correlation, not seen in the women, between waist circumference and FEV1. Conclusion: Pulmonary function is altered in women suffering from class I and II obesity. In obese men, although pulmonary function is unaffected by BMI, we observed a significant negative correlation between BMI and ERV. We can conclude that pulmonary function is influenced by waist circumference in men suffering from class I and II obesity.

Keywords: Respiratory function tests. Spirometry. Body mass index. Obesity.

Objective: Pregnancy brings about significant changes in respiratory function, as evidenced by alterations in lung volumes and capacities, which are attributable to the mechanical impediment caused by the growing foetus. This study was undertaken in order to identify changes in respiratory function during normal pregnancy and to determine whether such changes are more pronounced in twin pregnancy than in singleton pregnancy. Methods: Respiratory function was assessed in 50 women with twin pregnancies and in 50 women with singleton pregnancies (during the third trimester in both groups), as well as in 50 non-pregnant women. We measured the following pulmonary function test parameters: FVC; FEV1; PEF rate; FEV1/FVC ratio; FEF25-75%; and maximal voluntary ventilation. Results: All respiratory parameters except the FEV1/FVC ratio were found to be lower in the pregnant women than in the non-pregnant women. We found no significant differences between women with twin pregnancies and those with singleton pregnancies, in terms of respiratory function. Conclusions: Despite its higher physiological demands, twin pregnancy does not appear to impair respiratory function to any greater degree than does singleton pregnancy.

Keywords: Respiratory function tests; Respiratory mechanics; Pregnancy, twin; Pregnancy.

Objective: To determine cell profiles, as well as to identify CD4+ and CD8+ lymphocyte subgroups, in induced sputum (IS) and peripheral venous blood (PVB) of patients with chronic obstructive pulmonary disease (COPD). Methods: Total cell counts and counts of individual cell types, including CD4+ and CD8+ T lymphocytes, were determined in the IS and PVB of 85 subjects (38 with COPD without exacerbation, 29 smokers without obstruction and 18 nonsmokers). Mann-Whitney and Spearman non-parametric tests were used in the statistical analysis, and values of p < 0.05 were considered statistically significant. Results: Comparing the IS of subjects with COPD to that of nonsmokers, neutrophil, eosinophil and CD8+ T lymphocyte counts were higher (respectively p = 0.005, p < 0.05 and p < 0.05), whereas the percentage of macrophages was lower (p = 0.003). There were weak linear correlations (r2 < 0.1) between each cell type in IS and forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and FEV1/FVC ratio. Eosinophil and CD8+ T lymphocyte counts were also higher in PVB (p = 0.04 and p = 0.02). Conclusions: In patients with stable COPD, CD8+ T lymphocyte counts were higher in PVB, whereas total leukocyte counts were similar to those of the other two groups analyzed, suggesting systemic inflammatory involvement. The CD8+ T lymphocyte count in blood can be a useful marker of systemic inflammation and can help identify smokers who already present a COPD inflammatory pattern.

Keywords: Sputum; T-lymphocytes; Neutrophils; Macrophages; Eosinophils; Pulmonary disease, chronic obstructive.