Objective: Pulmonary disease in cystic fibrosis (CF) is characterised by recurrent episodes of pulmonary exacerbations (PExs), with acute and long-term declines in lung function (FEV1). The study sought to determine whether routine spirometry increases the frequency of PEx diagnosis, resulting in benefits to long-term pulmonary function. Methods: CF patients in the 5- to 18-year age bracket were followed for 1 year, during which they underwent spirometry before every medical visit. The main variables were the frequency of PEx diagnosis and use of antibiotics; the use of spirometry as a criterion for PEx diagnosis (a decline = 10% in baseline FEV1); and median percent predicted FEV1 over time. The data were compared with those for the previous 24-month period, when spirometry was performed electively every 6 months. Results: The study included 80 CF patients. PExs were diagnosed in 27.5% of the visits, with a mean frequency of 1.44 PExs per patient/year in 2014 vs. 0.88 PExs per patient/year in 2012 (p = 0.0001) and 1.15 PExs per patient/year in 2013 (p = 0.05). FEV1 was used as a diagnostic feature in 83.5% of PExs. In 21.9% of PExs, the decision to initiate antibiotics was solely based on an acute decline in FEV1. The median percent predicted FEV1 during the follow-up year was 85.7%, being 78.5% in 2013 and 76.8% in 2012 (p > 0.05). The median percent predicted FEV1 remained above 80% during the two years after the study. Conclusions: Routine spirometry is associated with higher rates of diagnosis and treatment of PExs, possibly impacting long-term pulmonary function.

Keywords: Cystic fibrosis; Respiratory function tests; Respiratory tract infections; Spirometry.

Evidence-based techniques have been increasingly used in the creation of clinical guidelines and the development of recommendations for medical practice. The use of levels of evidence allows the reader to identify the quality of scientific information that supports the recommendations made by experts. The objective of this review was to address current concepts related to the clinical impact, diagnosis, and treatment of Pseudomonas aeruginosa infections in patients with cystic fibrosis. For the preparation of this review, the authors defined a group of questions that would be answered in accordance with the principles of PICO-an acronym based on questions regarding the Patients of interest, Intervention being studied, Comparison of the intervention, and Outcome of interest. For each question, a structured review of the literature was performed using the Medline database in order to identify the studies with the methodological design most appropriate to answering the question. The questions were designed so that each of the authors could write a response. A first draft was prepared and discussed by the group. Recommendations were then made on the basis of the level of scientific evidence, in accordance with the classification system devised by the Oxford Centre for Evidence-Based Medicine, as well as the level of agreement among the members of the group.

Keywords: Cystic fibrosis/diagnosis; Cystic fibrosis/drug therapy; Pseudomonas aeruginosa; Evidence-based medicine.

Objective: To analyze the effects of Pilates mat exercises in patients with cystic fibrosis (CF). Methods: This was a clinical trial involving 19 CF patients recruited from either the CF Outpatient Clinic of the State University at Campinas Hospital de Clínicas or the Children's Institute of the University of São Paulo School of Medicine Hospital das Clínicas. All of the patients performed Pilates mat exercises for four months (one 60-min session per week). The variables studied (before and after the intervention) were respiratory muscle strength, MIP, MEP, FVC, and FEV1. Results: After the intervention, MIP was significantly higher in the male patients (p = 0.017), as were MIP and MEP in the female patients (p = 0.005 and p = 0.007, respectively). There were no significant differences between the pre- and post-intervention values of FVC or FEV1, neither in the sample as a whole nor among the patients of either gender. Conclusions: Our results show that Pilates mat exercises have beneficial effects on respiratory muscle strength in CF patients. (Brazilian Registry of Clinical Trials - ReBEC; identification number RBR-86vp8x [http://www.ensaiosclinicos.gov.br])

Keywords: Cystic fibrosis; Muscle strength; Exercise movement techniques; Respiratory function tests.

Although cystic fibrosis (CF) is an irreversible genetic disease, advances in treatment have increased the life expectancy of CF patients. Upper airway involvement, which is mainly due to pathological changes in the paranasal sinuses, is prevalent in CF patients, although many are only mildly symptomatic (with few symptoms). The objective of this literature review was to discuss the pathophysiology and current therapeutic management of chronic rhinosinusitis (CRS) in CF patients. The review was based on current evidence, which was classified in accordance with the Oxford Centre for Evidence-Based Medicine criteria. When symptomatic, CRS with nasal polyps can affect quality of life and can lead to pulmonary exacerbations, given that the paranasal sinuses can be colonized with pathogenic bacteria, especially Pseudomonas aeruginosa. Infection with P. aeruginosa plays a crucial role in morbidity and mortality after lung transplantation in CF patients. Although clinical treatment of the upper airways is recommended as initial management, this recommendation is often extrapolated from studies of CRS in the general population. When sinonasal disease is refractory to noninvasive therapy, surgery is indicated. Further studies are needed in order to gain a better understanding of upper airway involvement and improve the management of CRS in CF patients, with the objective of preserving lung function and avoiding unnecessary invasive procedures.

Keywords: Nose diseases; Cystic fibrosis; Nasal polyps; Paranasal sinuses; Sinusitis.

Objective: To evaluate the impact of the elexacaftor/tezacaftor/ivacaftor (ELX/TEZ/IVA) combination on the small airways in adults with cystic fibrosis (CF), a genetic disorder that primarily affects the respiratory system, leading to progressive lung disease. In CF, the small airways play a critical role, contributing to chronic symptoms such as cough, sputum production, and dyspnea. Methods: This was a single-center, retrospective observational study of adults with CF treated with ELX/TEZ/IVA for 12 months. We compared the patients who were homozygous for the F508del mutation of the CF transmembrane conductance regulator (CFTR) gene with those who were heterozygous for that mutation, in terms of lung function outcomes (FEV1, FEF25-75%, and the RV/TLC ratio) and the extent of non-homogeneous ground-glass opacity. Among the patients within the cohort, the same parameters were evaluated separately in those who had advanced lung disease and in those who had previously undergone CFTR modulator therapy. Results: There was a significant post-treatment improvement in lung function, with a median increase of 0.42 L/s in the FEF25-75% (p < 0.001) and a 5% reduction in the mean RV/TLC ratio (p < 0.001). There was a trend toward a higher improvement the F508del homozygous patients. A significant reduction in non-homogeneous ground-glass opacity was observed in 79.5% of the patients. Among the patients with advanced lung disease, there were notable post-treatment improvements in all of the parameters assessed. Conclusions: Our results highlight the positive impact that ELX/TEZ/IVA treatment can have on small airway function in patients with CF, with potential benefits even for those with advanced lung disease. Further research is needed in order to evaluate the long-term effects of this treatment and its relationship with patient-reported outcomes.

Keywords: Cystic fibrosis/diagnostic imaging; Lung/physiopathology; Respiratory function tests; Lung/drug effects; Lung/diagnostic imaging; Cystic fibrosis/drug therapy.

Objective: To evaluate whether anthropometric and dietary intake indicators are predictors of pulmonary function in cystic fibrosis (CF) patients. Methods: This was a cross-sectional study involving 69 patients (age range, 5.4-16.5 years) diagnosed with CF under follow-up at the Hospital de Clínicas de Porto Alegre, located in the city of Porto Alegre, Brazil. Anthropometric assessment was based on body mass index (BMI), mid-arm muscle circumference (MAMC), and triceps skinfold thickness (TST). Dietary intake was assessed by using recall data, which were compared with the recommended dietary allowances. Pulmonary function was assessed by ventilatory capacity, expressed as FEV1. Prevalence ratios for the outcome studied (FEV1 < 80% of predicted) were calculated by indicator. Results: In patients with MAMC and TST below the 25th percentile, the prevalence of FEV1 < 80% of predicted was significantly higher than in those with higher MAMC and TST (p < 0.001 and p = 0.011, respectively). In comparison with other patients, those with a BMI below the 50th percentile showed a 4.43 times higher prevalence of FEV1 < 80% of predicted (95% CI: 1.58-12.41), and that prevalence was 2.54 times higher in those colonized with methicillin-resistant Staphylococcus aureus (MRSA) than in those not so colonized (95% CI: 1.43-4.53). The association between dietary intake and the prevalence of FEV1 < 80% of predicted was of only borderline significance (95% CI: 0.95-3.45). Conclusions: Not being colonized with MRSA and having a BMI above the 50th percentile appear to preserve pulmonary function in CF patients.

Keywords: Cystic fibrosis; Respiratory function tests; Nutrition assessment; Energy intake.

Objectives: To examine the relationship between chronic bacterial infection and pulmonary hypertension, using Doppler echocardiography, in patients with cystic fibrosis (CF). Methods: A prospective cross-sectional study involving CF patients (≥ 16 years of age) admitted to a program for adults with the disease. The study included 40 patients with a mean age of 23.7 ± 6.3 years. Patients were submitted to clinical evaluation, Doppler echocardiography, pulmonary function tests, chest X-rays and sputum cultures of Pseudomonas aeruginosa and Burkholderia cepacia. Results: In terms of the following variables, no significant differences were found between P. aeruginosapositive patients and P. aeruginosa-negative patients: clinical score (p = 0.472); forced expiratory volume in one second (FEV1; p = 0.693); radiological score (p = 0.760); tricuspid regurgitant jet velocity (TRV, p = 0.330); diameter of the right ventricle (DRV, p = 0.191); and right ventricular/pulmonary artery (RV/PA) systolic acceleration time (SAT, p = 0.330). B. cepacia-positive patients presented significantly lower FEV1 than did B. cepacia-negative patients (p = 0.011). No significant differences were found between B. cepacia-positive patients and B. cepacia-negative patients regarding the following variables: clinical score (p = 0.080); radiological score (p = 0.760); TRV (p = 0.613); DRV (p = 0.429); and RV/PA SAT (p = 0.149). Conclusions: Chronic infection with P. aeruginosa or B. cepacia presented no association with pulmonary hypertension in adult CF patients. Pulmonary function was worse in B. cepacia-positive patients than in P. aeruginosa-positive patients.

Keywords: Cystic fibrosis; Bacterial infections; Hypertension, pulmonary; Echocardiography, Doppler.

Objetivo: Analisar as características funcionais pulmonares, a resposta farmacodinâmica a um broncodilatador e sua prescrição em pacientes com diagnóstico de fibrose cística (FC). Métodos: Estudo de coorte retrospectivo de pacientes (6-18 anos) com diagnóstico de FC acompanhados em um centro de referência, capazes de realizar testes de função pulmonar (TFP) entre 2008 e 2010. Foram analisados CVF, VEF1 e FEF25-75%, em percentual do previsto, antes e após prova broncodilatadora (pré-BD e pós-BD, respectivamente) de 312 TFP. Foram realizadas ANOVA para medidas repetidas e comparações múltiplas. Resultados: Foram incluídos no estudo 56 pacientes. Desses, 37 e 19, respectivamente, tinham resultados de TFP entre 2008 e 2010 e apenas em 2009-2010, formando dois grupos. No grupo com TFP nos três anos estudados, houve redução significativa em VEF1 pós-BD em 2008-2010 (p = 0,028) e 2009-2010 (p = 0,036) e em FEF25-75% pré-BD e pós-BD em todas as comparações múltiplas (2008 vs. 2009; 2008 vs. 2010; e 2009 vs. 2010). No grupo com TFP apenas em 2009-2010, não houve diferenças significativas em nenhuma das comparações das variáveis estudadas. Dos 312 TFP, somente 24 (7,7%) apresentaram resposta significativa ao broncodilatador e pertenciam a pacientes sem prescrição de broncodilatador durante o período estudado. Conclusões: Houve perda funcional, com indicação de doença pulmonar progressiva, nos pacientes com FC estudados. Houve maiores alterações no FEF25-75%, sugerindo o comprometimento inicial de vias aéreas menores.

Keywords: Fibrose cística; Testes de função respiratória; Broncodilatadores.

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: To investigate the impact of a pulmonary rehabilitation program on the functional capacity and on the quality of life of patients on waiting lists for lung transplantation. Methods: Patients on lung transplant waiting lists were referred to a pulmonary rehabilitation program consisting of 36 sessions. Before and after the program, participating patients were evaluated with the six-minute walk test and the Medical Outcomes Study 36-item Short-Form Health Survey (SF-36). The pulmonary rehabilitation program involved muscle strengthening exercises, aerobic training, clinical evaluation, psychiatric evaluation, nutritional counseling, social assistance, and educational lectures. Results: Of the 112 patients initially referred to the program, 58 completed it. The mean age of the participants was 46  14 years, and females accounted for 52%. Of those 58 patients, 37 (47%) had pulmonary fibrosis, 13 (22%) had pulmonary emphysema, and 18 (31%) had other types of advanced lung disease. The six-minute walk distance was significantly greater after the program than before (439 ± 114 m vs. 367 ± 136 m, p = 0.001), the mean increase being 72 m. There were significant point increases in the scores on the following SF-36 domains: physical functioning, up 22 (p = 0.001), role-physical, up 10 (p = 0.045); vitality, up 10 (p < 0.001); social functioning, up 15 (p = 0.001); and mental health, up 8 (p = 0.001). Conclusions: Pulmonary rehabilitation had a positive impact on exercise capacity and quality of life in patients on lung transplant waiting lists.

Keywords: Rehabilitation; Lung transplantation; Quality of life; Exercise; Exercise tolerance.

Objective: To determine the prevalence of pulmonary hypertension (PH) in patients with cystic fibrosis (CF), to compare clinical characteristics, radiographic scores, pulmonary function, and echocardiographic parameters in patients with and without PH, and to correlate echocardiographic findings with clinical characteristics, radiographic scores, and pulmonary function. Methods: This was a prospective, cross-sectional study involving clinically stable patients (aged 16 or older) enrolled in an adult CF program. The patients were submitted to clinical evaluation, Doppler echocardiography, pulmonary function tests, and chest X-rays. Results: Tricuspid regurgitant jet velocity (TRV) was obtained in 37 of the 40 patients studied. The prevalence of PH was 49% with a TRV cut-off of 2.5 m/s (18 patients) and 30% with a TRV cut-off of 2.8 m/s (11 patients). Peripheral oxygen saturation (SpO2) at rest, clinical score, forced expiratory volume in one second (FEV1), and forced vital capacity (FVC) were significantly lower in the group with PH. The TRV was found to correlate significantly with SpO2 at rest (p < 0.001), clinical score (p < 0.001), radiographic score (p = 0.030), FEV1 in liters (p < 0.001) and in % of predicted (p < 0.001), and FCV in liters (p = 0.008) and in % of predicted (p = 0.001). The single best predictor of TRV was SpO2 at rest (p < 0.001). Conclusion: The high prevalence of PH in the CF patients studied suggests that PH should be considered in the evaluation and follow-up treatment of such patients. The best predictor of PH was SpO2 at rest.

Keywords: Cystic fibrosis; Tricuspid valve/physiopathology; Hypertension, pulmonary; Echocardiography, Doppler.

Objective: To study correlations among pulmonary function, chest radiology and clinical status in cystic fibrosis. Methods: A retrospective cross-sectional study was performed to evaluate chest X-rays and clinical charts of patients treated at the Hospital de Clínicas de Porto Alegre. Spirometry findings, Shwachman-Kulczycki (S-K) scores and Brasfield scores were analyzed. Results: The final sample consisted of 40 patients (mean age 9.72 ± 3.27). The following mean S-K scores were obtained: total, 80.87 ± 10.24; general activity, 24.75 ± 1.1; physical examination, 18.87 ± 4.59; nutrition, 21.87 ± 4.18; radiology, 15.37 ± 5.23. The mean Brasfield score was 18.2 ± 4. The pulmonary function test results, in percentage of predicted, were as follows: forced vital capacity (FVC), 82.99 ± 14.36%; forced expiratory volume in one second (FEV1), 83.62 ± 18.26%; and forced expiratory flow between 25 and 75% of FVC (FEF25-75), 74.63 ± 2.53%. The S-K score correlated moderately with FVC, whereas it correlated strongly with FEV1 and FEF25-75. The Brasfield score correlated strongly with the S-K total and radiology score, whereas it correlated moderately with pulmonary function. Physical examination correlated moderately with FVC, FEV1 and FEF25-75; as did nutrition with FEF25-75; and radiology with FEV1 and FEF25-75. General activity was the domain that had the greatest influence on the total S-K score. Conclusions: These two scoring systems are complementary, correlating with each other, as well as with pulmonary function tests. The radiology domain of the S-K scoring system is a good alternative to the Brasfield score.

Keywords: Cystic fibrosis; Spirometry; Lung/radiography.

Objectives: To evaluate the evolution pattern of dynamic pulmonary flow and volume in cystic fibrosis patients and analyze the relation between the severity of ventilatory attacks and age, gender, genotype and pulmonary colonization. Methods: At the Pediatric Pulmonary Unit and Pulmonary Service of Hospital de Clínicas of Porto Alegre, 243 spirometries performed between 1987 and 1999 in 52 cystic fibrosis patients older than four years of age were reviewed. From the patients' medical records the following informations were extracted: age at diagnosis, genetic data, bronchial colonization and absolute as well as percent values of the flows and volumes of the best annual spirometry. Results: The age of the patients ranged from four to 26 years (mean = 13.04 ± 4.82). Out of the 52 patients, 49 (94%) had at least one sputum culture with P. aeruginosa, 45 (86%) with S. aureus and 13 (25%) with B. cepacia. At initial evaluation, that included patients four to six years old (n = 40), mean values for FVC and FEV1 were 114.24% and 112.25%, respectively. Mean FVC remained above baseline until 18 years of age, when it abruptly dropped to 67.2% (p = 0.0002). Mean FEV1 values dropped to less than 80% at ten years and was 50% at 18 years (p < 0.00001). The FEV1/FVC% relationship, the most obstruction sensitive index, was observed to be reduced as early as initial evaluation. It was 85% between four and six years and gradually decreased to 63% at 18 years. The mean values of FEF50, FEF75 and FMEF were initially normal (94%, 80% and 90%, respectively), showed a greater and earlier statistically significant decline, and reached to 37%, 12.5% and 19%, respectively, at 18 years. Although a tendency to lower terminal flow was seen in the girls, the differences were not statistically significant. Significant correlations between pulmonary function and the airway colonizator or genotype were not detected statistic. Conclusion: The evolution pattern of pulmonary function alterations found in these patients is consistent with those reported in the literature, where obstructive ventilatory disorders with early terminal flow reduction and late FVC onset predominate.

Keywords: Spirometry. Cystic fibrosis. Pulmonary ventilatory.

Objective: There is evidence that asthma is associated with an increase in psychiatric symptoms and mental disorders. This association can make it difficult to achieve asthma control. The purpose of this study was to determine whether the level of asthma control is associated with anxiety and depression. Methods: A cross-sectional study involving 78 patients with confirmed moderate or severe asthma and under regular treatment at the Asthma Outpatient Clinic of the Federal University of São Paulo Hospital São Paulo, in the city of São Paulo, Brazil. The patients were divided into two groups by asthma control status, as assessed by the asthma control test, and were subsequently compared in terms of demographic, clinical, and spirometric data, as well as scores for asthma quality of life and hospital anxiety/depression. Results: The sample was predominantly female. Of the 78 patients, 49 (63%) were classified as having uncontrolled asthma. The prevalence of anxiety and of anxiety+depression was significantly higher among patients with uncontrolled asthma than among those with controlled asthma (78% and 100%; p = 0.04 and p = 0.02, respectively), whereas there were no differences between the two groups in terms of the prevalence of depression, spirometry results, or quality of life score. Conclusions: In this sample, the prevalence of anxiety symptoms was higher in the patients with uncontrolled asthma than in those with controlled asthma.In the evaluation of asthma patients, the negative impact of mood states ought to be taken into consideration when asthma control strategies are being outlined.

Keywords: Asthma; Anxiety; Depression; Cross-sectional studies.

Objective: To determine the effects that mutation of the cystic fibrosis transmembrane conductance regulator (CFTR) gene and deletion of the glutathione S-transferase (GST) genes mu-1 (GSTM1) and theta-1 (GSTT1) have on the clinical course of cystic fibrosis (CF) in patients residing in the southeastern region of Brazil. Methods: The study sample consisted of all consecutive CF patients treated at the Hospital de Clínicas School of Medical Sciences of the State University at Campinas between March of 2002 and March of 2005. We included 66 CF patients. Genomic DNA was analyzed by polymerase chain reaction and restriction endonuclease digestion for the identification of the genotypes. Results: The F508 mutation of the CFTR gene was found in 44 patients (66.7%). The null genotypes GSTM1, GSTT1 and GSTM1/GSTT1 were found in 40.9%, 15.2%, and 3.0% of the patients, respectively. The F508 CFTR mutation was more common in patients diagnosed with CF before 2.5 years of age than in those diagnosed later (75.5% vs. 41.2%; p = 0.008). The frequency of the F508 CFTR mutation, as well as of the GSTM1 and GSTT1 genotypes, was not found to be associated with gender, ethnicity, pulmonary disease status, or pancreatic disease status. Conclusions: When the patients were stratified by clinical and epidemiological features, the frequencies of the GSTM1 and GSTT1 null genotypes were similar, suggesting that the inherited absence of these enzymatic pathways does not alter the course of CF. However, the high frequency of the F508 CFTR mutation found in younger children suggests that it influences the age at diagnosis of CF in this region of Brazil.

Keywords: : Cystic fibrosis; Cystic fibrosis transmembrane conductance regulator; Glutathione transferase.

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.

Cystic fibrosis (CF) is an autosomal recessive genetic disorder characterized by dysfunction of the CFTR gene. It is a multisystem disease that most often affects White individuals. In recent decades, various advances in the diagnosis and treatment of CF have drastically changed the scenario, resulting in a significant increase in survival and quality of life. In Brazil, the current neonatal screening program for CF has broad coverage, and most of the Brazilian states have referral centers for the follow-up of individuals with the disease. Previously, CF was limited to the pediatric age group. However, an increase in the number of adult CF patients has been observed, because of the greater number of individuals being diagnosed with atypical forms (with milder phenotypic expression) and because of the increase in life expectancy provided by the new treatments. However, there is still great heterogeneity among the different regions of Brazil in terms of the access of CF patients to diagnostic and therapeutic methods. The objective of these guidelines was to aggregate the main scientific evidence to guide the management of these patients. A group of 18 CF specialists devised 82 relevant clinical questions, divided into five categories: characteristics of a referral center; diagnosis; treatment of respiratory disease; gastrointestinal and nutritional treatment; and other aspects. Various professionals working in the area of CF in Brazil were invited to answer the questions devised by the coordinators. We used the PubMed database to search the available literature based on keywords, in order to find the best answers to these questions.

Keywords: Cystic fibrosis/diagnosis; Cystic fibrosis/therapy; Cystic fibrosis/complications; Practice guideline.

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.