Objetivo: Medir a resistência de vias aéreas utilizando a técnica de resistência do interruptor (Rint) em pacientes com fibrose cística (FC) e correlacioná-la com parâmetros espirométricos, assim como avaliar a acurácia de Rint para determinar a resposta das vias aéreas a um broncodilatador. Métodos: Estudo transversal com 38 crianças e adolescentes com FC acompanhados no Ambulatório de FC do Hospital São Lucas, em Porto Alegre (RS). Após a determinação de Rint, os pacientes foram submetidos à espirometria. Para a avaliação da resposta ao broncodilatador, as medições foram repetidas após o uso de salbutamol inalatório. Resultados: Houve uma forte correlação entre o inverso de Rint e VEF1 (r = 0,8; p < 0,001) e moderadas correlações entre o inverso de Rint e FEF25-75% (r = 0,74; p < 0,001) e entre o inverso de Rint e índice de massa corpórea (r = 0,62; p < 0,001). A curva ROC foi utilizada na comparação da resposta ao broncodilatador determinada por Rint com aquela determinada por valores espirométricos. Para um ponto de corte de −28% para Rint, a área sob a curva foi de 0,75, com uma sensibilidade de 66% e uma especificidade de 82%. Conclusões: Nossos achados indicam que Rint apresenta uma boa correlação com parâmetros espirométricos, embora a técnica Rint não tenha sido suficientemente acurada para substituir a espirometria na avaliação da resposta ao broncodilatador.

Keywords: Testes de função respiratória; Fibrose cística; Espirometria; Resistência das vias respiratórias.

Objective: To compare two methods of respiratory inductive plethysmography (RIP) calibration in three different positions. Methods: We evaluated 28 healthy subjects (18 women and 10 men), with a mean age of 25.4 ± 3.9 years. For all of the subjects, isovolume maneuver calibration (ISOCAL) and qualitative diagnostic calibration (QDC) were used in the orthostatic, sitting, and supine positions. In order to evaluate the concordance between the two calibration methods, we used ANOVA and Bland-Altman plots. Results: The values of the constant of proportionality (K) were significantly different between ISOCAL and QDC in the three positions evaluated: 1.6 ± 0.5 vs. 2.0 ± 1.2, in the supine position, 2.5 ± 0.8 vs. 0.6 ± 0.3 in the sitting position, and 2.0 ± 0.8 vs. 0.6 ± 0.3 in the orthostatic position (p < 0.05 for all). Conclusions: Our results suggest that QDC is an inaccurate method for the calibration of RIP. The K values obtained with ISOCAL reveal that RIP should be calibrated for each position evaluated.

Keywords: Plethysmography; Respiratory mechanics; Posture; Calibration.

Objective: The interrupter technique is used for determining interrupter resistance (Rint) during quiet breathing. This noninvasive method requires minimal cooperation and can therefore be useful in evaluating airway obstruction in uncooperative children. To date, no reference values have been determined for Rint in a Brazilian population. The objective of this study was to define a prediction equation for airway resistance using the interrupter technique for healthy children aged 3-13 years. Methods: This was a prospective, cross-sectional study involving preschool and school children in Porto Alegre, Brazil, in whom Rint was measured during peak expiratory flow. Results: ­One-hundred and ninety-three children were evaluated. Univariate analysis using linear regression showed that height, weight and age correlated significantly and independently with Rint. Multiple regression with height, weight, age and gender as variables resulted in a model in which only height and weight were significant, independent predictors of Rint. Collinearity was identified among height, weight and age. ­Conclusions: Reference values and an equation for calculating Rint in healthy children were obtained and are adjusted for height.

Keywords: Respiratory function tests; Airway resistance; Diagnostic techniques, respiratory system; Airway obstruction/diagnosis; Reference values.

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 determine the agreement between interrupter resistance (Rint) and airway resistance (Raw) by plethysmography in order to verify the clinical applicability of the interrupter technique. Methods: The Rint technique was performed with the patients in a sitting position, during exhalation, with a nose clip and cheek support. Plethysmography was carried out in accordance with standard protocols. All measurements were taken prior to and after the administration of an inhaled bronchodilator via a metered dose inhaler with a spacer. Results: The study comprised 99 consecutive patients referred to the Porto Alegre Hospital de Clínicas, located in the city of Porto Alegre, Brazil, for pulmonary function testing. Patient ages ranged from 18 to 82 years, and 52 of the patients were women. In the patients with FEV1 ≥ 60% of predicted, there was good agreement between the methods (r = 0.8; intraclass correlation coefficient = 0.8). The Rint values were lower than were those of Raw by plethysmography in the patients with more severe disease. However, there was good agreement between Rint ≥ 4 cmH2O  L−1  s−1 and Raw by plethysmography > 2.5 cmH2O  L−1  s−1 (likelihood ratio > 8; kappa coefficient = 0.73). Conclusions: In the patients with less severe disease, there was good agreement between Rint and Raw by plethysmography. The agreement between the two methods was also strong regarding the detection of an increase in Raw. The Rint technique is a potentially useful method for the evaluation of adult patients.

Keywords: Plethysmography; Airway resistance; Diagnostic techniques, respiratory system; Respiratory function tests; Airway obstruction/diagnosis.

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 determine the effect that re-education of the thoracic and abdominal muscles has on the respiratory muscle strength of patients with cystic fibrosis evaluated over time at the Cystic Fibrosis Outpatient Clinic of the Universidade Católica de Brasília (Catholic University of Brasília). Methods: The sample consisted of 29 cystic fibrosis patients, characterized based on anthropometric, genetic and bacterial colonization data. The patients were submitted to physical therapy sessions, involving re-education of the respiratory muscles, twice a week for four months. Spirometry, pressure manometry and anthropometry were performed before and after each session. Results: Comparing baselines values to those obtained after physical therapy, increases in maximum inspiratory pressure and maximum expiratory pressure were observed in all patients, those without any obstructive respiratory disease and those with mild obstructive respiratory disease (p < 0.05). A positive correlation between age and maximum expiratory pressure was observed for most of the patients. Maximum inspiratory pressure correlated positively with age only in the group with mild obstructive respiratory disease (p = 0.012; r = 0.817). In female patients and in the group of patients without obstructive respiratory disease, a negative correlation was observed between maximum expiratory pressure and colonization with Pseudomonas aeruginosa (p = 0.036; r = -0.585). Conclusion: Use of the thoracic and abdominal muscle re-education technique increased respiratory muscle strength in the cystic fibrosis patients studied, a finding that underscores the importance of including physical therapy in the treatment of these patients.

Keywords: Cystic fibrosis/rehabilitation; Physical therapy technique; Respiratory muscles; Forced expiratory volume; Inspiratory capacity; Vital capacity

Objective: The objective of this study was to evaluate the applicability of a modified version of the Saint George's Respiratory Questionnaire. The version evaluated elicits "agree" and "do not agree", rather than "yes" and "no", responses. The intention is to facilitate the comprehension of double-negative questions and to promote better recollection of symptoms by patients by shortening their symptom histories from 12 months to 3 months. Methods: A total of 30 clinically stable patients with chronic obstructive pulmonary disease were evaluated. The Saint George's Respiratory Questionnaire and the modified version of the same were administered 15 days apart. Results: All of the patients presented health-related alterations in their quality of life. Comparing mean scores between the two questionnaires, the greatest difference was seen in the Symptoms domain. No significant differences were found in any of the remaining domains or in the total scores. In a subsequent analysis, significant correlations between the two questionnaires were found in all domains: Symptoms (r = 0.71; p < 0.001); Activity (r = 0.75; p < 0.001); Impact (r = 0.73; p < 0.001) and Total (r = 0.86; p < 0.001). Conclusion: The modified version of the Saint George's Respiratory Questionnaire is as effective as the original in gauging quality of life. However, various symptoms recollection time frames should be investigated in order to determine which would be the best time frame to employ in the analysis.

Keywords: Pulmonary disease, chronic obstructive; Quality of life; Reproducibility of results; Cross-cultural comparison; Questionnaires

Objectives: To evaluate the self-reported degree of adherence to treatment in patients with cystic fibrosis (CF), investigating associations with characteristics of the disease and with the degree of adherence perceived by health professionals. Methods: This was a prospective, cross-sectional study involving patients with CF monitored at a Program for Adults with CF. The degree of adherence was evaluated using a questionnaire. Patients were divided into two groups: greater degree of adherence and moderate/poor degree of adherence. Clinical data, Shwachman-Kulczycki clinical score, Brasfield radiographic score and spirometry data were obtained for all patients. Results: Out of 38 patients studied, 31 (81.6%) were classified as presenting a greater degree of adherence and 7 (18.4%) as presenting a moderate/poor degree of adherence. The self-reported patient adherence score correlated with the clinical score (r = −0.36, p = 0.028). The self-reported patient adherence score (median = 0.79) was higher than that perceived by health professionals (median = 0.71, p = 0.003). A greater degree of adherence was self-reported for respiratory therapy (by 84.2%), exercise (by 21.1%), prescribed diet (by 65.8%), pancreatic enzymes (by 96.3%), vitamins (by 79.4%), inhaled antibiotic therapy (by 76.7%) and inhaled DNase (by 79.4%). Conclusions: Self-reported adherence of patients attending a Program for Adults with CF was good. The self-reported patient adherence score correlated inversely with the clinical score. Self-reported patient adherence was greater than the adherence perceived by health professionals.

Keywords: Cystic fibrosis; Patient compliance; Therapeutics.

Objective: To assess the quality of life (QoL) of patients with cystic fibrosis (CF) followed at a university referral center for CF. Methods: A cross-sectional study involving application of the Cystic Fibrosis Questionnaire (CFQ) and Shwachman score in CF patients between April of 2008 and June of 2009. Results: The sample consisted of 75 patients. The mean age was 12.5 ± 5.1 years (range, 6.1-26.4 years). The patients were divided into three groups by age in years: group I (< 12), II (12-14), and III (≥ 14). The highest and lowest CFQ scores were for the nutrition domain in group III (89.3 ± 16.2) and the social domain in group II (59.5 ± 22.3), respectively. Groups I and III differed significantly regarding the treatment domain (p = 0.001). Regarding Shwachman scores, there were significant differences between patients scoring ≤ 70 and those scoring > 70 in the social (group I; p = 0.045), respiratory (group II; p = 0.053), and digestive (p = 0.042) domains. In group III, severity did not correlate with QoL. In groups I and II, patients with an FEV1 < 80% of predicted did not differ from other patients for any CFQ domain. However, in group III, values for the following domains were significantly lower in patients with an FEV1 < 80%: physical (p = 0.012); body image (p = 0.031); respiratory (p = 0.023), emotional (p = 0.041); and social role (p = 0.024). Conclusions: It is important to assess QoL in CF patients, because it can improve treatment compliance.

Keywords: Cystic fibrosis; Quality of life; Questionnaires.

Objective: To identify microorganisms in sputum samples of patients with stable non-cystic fibrosis bronchiectasis and to determine risk factors related to the isolation of Pseudomonas aeruginosa (PA) in those patients. Methods: Consecutive patients were recruited from a tertiary hospital outpatient clinic in the city of Fortaleza, Brazil. The patients were submitted to spirometry, six-minute walk test, HRCT, and sputum collection. Data on serum fibrinogen levels, disease severity, sputum color, and history of azithromycin treatment were collected. Results: The study included 112 patients, and females predominated (68%). The mean age was 51.6 ± 17.4 years. Most patients presented with mild-to-moderate disease (83%). The mean six-minute walk distance was 468.8 ± 87.9 m. Mean FEV1 and FVC, in % of predicted values, were 60.4 ± 21.8% and 69.9 ± 18.5%, respectively. The mean serum fibrinogen level was 396.1 ± 76.3 mg/dL. PA was isolated in 47 patients, other potentially pathogenic microorganisms (PPMs) were isolated in 31 patients, and non-PPMs were isolated in 34 patients. Purulent sputum was identified in 77 patients (68%). The patients with PA, when compared with those without it, presented with more severe disease, higher serum fibrinogen levels, and lower FVC%. In addition, purulent sputum and long-term azithromycin treatment were more common in those with PA. The multivariate regression analysis showed that the independent factors associated with PA were serum fibrinogen level > 400 mg/dL (OR = 3.0; 95% CI: 1.1-7.7) and purulent sputum (OR = 4.3; 95% CI: 1.6-11.3). Conclusions: In our sample, the prevalence of PA in sputum was 42%. Sputum color and inflammatory markers were able to predict the isolation of PA, emphasizing the importance of routine sputum monitoring.

Keywords: Bronchiectasis; Pseudomonas aeruginosa; Sputum/microbiology.

Objective: Many patients with proportional reductions in FVC and FEV1 on spirometry show no reduction in TLC. The aim of this study was to evaluate the role that measuring lung volumes and airway resistance plays in the correct classification of patients with a possible restrictive pattern on spirometry. Methods: This was a prospective study involving adults with reduced FVC and FEV1, as well as an FEV1/FV(C) ratio within the predicted range. Restrictive lung disease (RLD) was characterized by TLC below the 5th percentile, as determined by plethysmography. Obstructive lung disease (OLD) was characterized by high specific airway resistance, significant changes in post-bronchodilator FEV1, or an FEF25-75% < 50% of predicted, together with a high RV/TLC ratio. Nonspecific lung disease (NLD) was characterized by TLC within the predicted range and no obstruction. Combined lung disease (CLD) was characterized by reduced TLC and findings indicative of airflow obstruction. Clinical diagnoses were based on clinical suspicion, a respiratory questionnaire, and the review of tests of interest. Results: We included 300 patients in the study, of whom 108 (36%) were diagnosed with RLD. In addition, 120 (40%) and 72 (24%) were diagnosed with OLD/CLD and NLD, respectively. Among the latter, 24 (33%) were clinically diagnosed with OLD. In this sample, 151 patients (50.3%) were obese, and obesity was associated with all patterns of lung disease. Conclusions: Measuring lung volumes and airway resistance is often necessary in order to provide an appropriate characterization of the pattern of lung disease in patients presenting with a spirometry pattern suggestive of restriction. Airflow obstruction is common in such cases.

Keywords: Spirometry; Airway resistance; Lung volume measurements.

Cystic fibrosis-related diabetes (CFRD) is the principal extra-pulmonary complication of cystic fibrosis, occurring in 15-30% of adult cystic fibrosis patients. The number of cystic fibrosis patients who develop diabetes is increasing in parallel with increases in life expectancy. The aim of this study was to review the physiopathology, clinical presentation, diagnosis and treatment of CFRD. A bibliographic search of the Medline and Latin American and Caribbean Health Sciences Literature databases was made. Articles were selected from among those published in the last twenty years. Insulin deficiency, caused by reduced β-cell mass, is the main etiologic mechanism, although insulin resistance also plays a role. Presenting features of type 1 and type 2 diabetes, CFRD typically affects individuals of approximately 20 years of age. It can also be accompanied by fasting, non-fasting or intermittent hyperglycemia. Glucose intolerance is associated with worsening of nutritional status, increased morbidity, decreased survival and reduced pulmonary function. Microvascular complications are always present, although macrovascular complications are rarely seen. An oral glucose tolerance test is recommended annually for patients ≥ 10 years of age and for any patients presenting unexplained weight loss or symptoms of diabetes. Patients hospitalized with severe diseases should also be screened. If fasting hyperglycemia persists for more than 48 h, insulin therapy is recommended. Insulin administration remains the treatment of choice for diabetes and fasting hyperglycemia. Calories should not be restricted, and patients with CFRD should be managed by a multidisciplinary team.

Keywords: Cystic fibrosis; Diabetes mellitus.

Objective: To test the hypothesis that disease severity in patients with cystic fibrosis (CF) is correlated with an increased risk of sleep apnea. Methods: A total of 34 CF patients underwent clinical and functional evaluation, as well as portable polysomnography, spirometry, and determination of IL-1β levels. Results: Mean apnea-hypopnea index (AHI), SpO2 on room air, and Epworth Sleepiness Scale score were 4.8 ± 2.6, 95.9 ± 1.9%, and 7.6 ± 3.8 points, respectively. Of the 34 patients, 19 were well-nourished, 6 were at nutritional risk, and 9 were malnourished. In the multivariate model to predict the AHI, the following variables remained significant: nutritional status (β = −0.386; p = 0.014); SpO2 (β = −0.453; p = 0.005), and the Epworth Sleepiness Scale score (β = 0.429; p = 0.006). The model explained 51% of the variation in the AHI. Conclusions: The major determinants of sleep apnea were nutritional status, SpO2, and daytime sleepiness. This knowledge not only provides an opportunity to define the clinical risk of having sleep apnea but also creates an avenue for the treatment and prevention of the disease.

Keywords: Cystic fibrosis; Oxygenation; Sleep apnea, obstructive.

Pectus excavatum (PEX) is the most frequent congenital deformity of the anterior chest wall and is defined as the dislocation of the medial or inferior portion of the sternal region toward the spinal column. There are various ways to measure the deformity. In this study, we present an objective method of assessing such deformity, the anthropometric index for PEX (AI-PEX). The AI-PEX was developed in the Thoracic Surgery Department of the Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas. The anthropometric measurements are taken during the physical examination. We herein report two cases involving patients with PEX assessed using the AI-PEX and treated with the minimally invasive Nuss technique. The measurements were always taken at the point of greatest deformity. The patients were assessed on the day of the operation and again at 60 days after the surgery. The AI-PEX allowed us to obtain a satisfactory assessment of the defect. In both patients, the post-operative evolution was favorable.

Keywords: Thoracic wall; Thoracic surgery, Video-assisted; Funnel chest.

Objective: To profile the characteristics of adult patients with bronchiectasis, drawing comparisons between cystic fibrosis (CF) patients and those with bronchiectasis from other causes in order to determine whether it is rational to extrapolate the bronchiectasis treatment given to CF patients to those with bronchiectasis from other causes. Methods: A retrospective analysis of the medical charts of 87 patients diagnosed with bronchiectasis and under follow-up treatment at our outpatient clinic. Patients who had tuberculosis (current or previous) were excluded. We evaluated the clinical, functional, and treatment data of the patients. Results: Of the 87 patients with bronchiectasis, 38 (43.7%) had been diagnosed with CF, through determination of sweat sodium and chloride concentrations or through genetic analysis, whereas the disease was due to another etiology in 49 (56.3%), of whom 34 (39.0%) had been diagnosed with idiopathic bronchiectasis. The mean age at diagnosis was lower in the patients with CF than in those without (14.2 vs. 24.2 years; p < 0.05). The prevalence of symptoms (cough, expectoration, hemoptysis, and wheezing) was similar between the groups. Colonization by Pseudomonas aeruginosa or Staphylococcus aureus was more common in the CF patients (82.4 vs. 29.7% and 64.7 vs. 5.4%, respectively). Conclusions: The causes and clinical manifestations of bronchiectasis are heterogeneous, and it is important to identify the differences. It is crucial that these differences be recognized so that new strategies for the management of patients with bronchiectasis can be developed.

Keywords: Cystic fibrosis; Bronchiectasis/diagnosis; Bronchiectasis/therapy; Respiratory function tests.

Objective: To determine the prevalence of allergic bronchopulmonary aspergillosis (ABPA) in patients with cystic fibrosis treated at a referral center in the state of Bahia, Brazil. Methods: A cross-sectional study, with prospective data collection, carried out at the Cystic Fibrosis Referral Center of Bahia of the Octávio Mangabeira Specialized Hospital. We evaluated 74 patients diagnosed with cystic fibrosis, older than six years of age, treated between December 9, 2003 and March 7, 2005. We analyzed the following variables: gender, age, forced vital capacity, forced expiratory volume in one second, pharmacodynamic response, chest X-ray findings, facial sinus X-ray findings, wheezing, cultures for Aspergillus spp., total immunoglobulin E (IgE), specific IgE for Aspergillus fumigatus and immediate skin test reactivity to A. fumigatus antigen. Results: Of the 74 patients, 2 were diagnosed with ABPA. We found total IgE levels > 1,000 IU/mL in 17 (23%), positive immediate skin reactivity to A. fumigatus antigen in 19 (25.7%) and wheezing in 60 (81.1%). Conclusions: The prevalence of ABPA was 2.7%. The high levels of total IgE, high incidence of wheezing and high rate of immediate skin test reactivity to A. fumigatus antigen suggest that these patients should be carefully monitored due to their propensity to develop ABPA.

Keywords: Cystic fibrosis; Aspergillosis, allergic bronchopulmonary; Immunoglobulin E/diagnostic use; Hypersensitivity, immediate/diagnosis; Gliotoxin.

Objective: To compare patients with cystic fibrosis and healthy individuals in terms of their functional performance on the six-minute walk test (6MWT). Methods: A prospective, cross-sectional study involving healthy individuals and patients with cystic fibrosis treated at a referral university hospital in the city of Campinas, Brazil. The 6MWT was administered in accordance with the American Thoracic Society guidelines, and it was repeated after a 30-min rest period. For all of the participants, RR, HR, SpO2, and Borg scale scores were obtained. For the cystic fibrosis patients, nutritional status and spirometric values were determined. Patients with pulmonary exacerbation were excluded. Spearman's correlation coefficient and repeated measures ANOVA were used. Results: The cystic fibrosis group comprised 55 patients, and the control group comprised 185 healthy individuals. The mean ages were 12.2 ± 4.3 and 11.3 ± 4.3 years, respectively. The six-minute walk distance (6MWD) was significantly shorter in the cystic fibrosis group than in the control group for both tests (547.2 ± 80.6 m vs. 610.3 ± 53.4 m for the first and 552.2 ± 82.1 m vs. 616.2 ± 58.0 m for the second; p < 0.0001 for both). The 6MWD correlated with age, weight, and height only in the cystic fibrosis group. During the tests, SpO2 remained stable, whereas HR and RR increased. Conclusions: In our sample, functional performance on the 6MWT was poorer among the cystic fibrosis patients than among the healthy controls in the same age bracket, and we found immediate repetition of the test to be unadvisable.

Keywords: Cystic fibrosis; Exercise tolerance; Dyspnea.