Objective: The identification of persistent airway obstruction is key to making a diagnosis of COPD. The GOLD guidelines suggest a fixed criterion-a post-bronchodilator FEV1/FVC ratio < 70%-to define obstruction, although other guidelines suggest that a post-bronchodilator FEV1/FVC ratio < the lower limit of normal (LLN) is the most accurate criterion. Methods: This was an observational study of individuals = 40 years of age with risk factors for COPD who were referred to our pulmonary function laboratory for spirometry. Respiratory symptoms were also recorded. We calculated the prevalence of airway obstruction and of no airway obstruction, according to the GOLD criterion (GOLD+ and GOLD-, respectively) and according to the LLN criterion (LLN+ and LLN-, respectively). We also evaluated the level of agreement between the two criteria. Results: A total of 241 individuals were included. Airway obstruction was identified according to the GOLD criterion in 42 individuals (17.4%) and according to the LLN criterion in 23 (9.5%). The overall level of agreement between the two criteria was good (? = 0.67; 95% CI: 0.52-0.81), although it was lower among the individuals = 70 years of age (? = 0.42; 95% CI: 0.12-0.72). The proportion of obese individuals was lower in the GOLD+/LLN+ category than in the GOLD+/LLN- category (p = 0.03), as was the median DLCO (p = 0.04). Conclusions: The use of the GOLD criterion appears to be associated with a higher prevalence of COPD. The agreement between the GOLD and LLN criteria also appears to be good, albeit weaker in older individuals. The use of different criteria to define airway obstruction seems to identify individuals with different characteristics. It is essential to understand the clinical meaning of discordance between such criteria. Until more data are available, we recommend a holistic, individualized approach to, as well as close follow-up of, patients with discordant results for airway obstruction.

Keywords: Pulmonary disease, chronic obstructive; Airway obstruction; Spirometry.

Objective: To investigate the clinical characteristics of preterm infants with different severities of bronchopulmonary dysplasia (BPD) and disclose the high-risk factors of exacerbating BPD. Methods: Collection of clinical data of 91 preterm infants admitted to the NICU and diagnosed with BPD, categorized in groups according to the disease severity: 41 mild cases,, 24 moderate cases, and 26 severe cases. Comparison and analysis of perinatal risk factors, treatment, complications and prognosis of the infants with different severity degrees. Results: The severe group had a higher proportion of infants with congenital heart disease (CHD) higher than the moderate group (P < 0.05), and a higher ratio of pneumonia and mechanical ventilation (MV) = seven days than the mild group (P < 0.05). The severe group also presented higher reintubation incidence than both the mild and moderate groups (P < 0.05). The groups presented different (P < 0.05) incidence rates of hemodynamically significant patent ductus arteriosus (hsPDA) . Ridit analysis suggested that the premature infants (PIs) with hsPDA, multiple microbial pulmonary infections, or Klebsiella pneumoniae pneumonia had more severe illness. Conclusion: CHD, hsPDA, MV = seven days, reintubation, pneumonia, especially multiple microbial pulmonary infections, and Klebsiella pneumoniae pneumonia are correlated with the severity of BPD and can be used as BPD progression predictor.

Keywords: BPD; Preterm infant; CHD; hsPDA;, Pneumonia; Mechanical ventilation

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 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: To investigate the presence of airway obstruction by determining the FEV1/FVC and FEV1/slow vital capacity (SVC) ratios. Methods: This was a quantitative, retrospective cross-sectional study. The sample comprised 1,084 individuals who underwent spirometry and plethysmography in a central hospital in Lisbon, Portugal. The study sample was stratified into six groups, by pulmonary function. Results: The analysis of the FEV1/FVC ratio revealed the presence of airway obstruction in 476 individuals (43.9%), compared with 566 individuals (52.2%) for the analysis of the FEV1/SVC ratio. In the airway obstruction, airway obstruction plus lung hyperinflation, and mixed pattern groups, the difference between SVC and FVC (SVC − FVC) was statistically superior to that in the normal pulmonary function, reduced FEF, and restrictive lung disease groups. The SVC − FVC parameter showed a significant negative correlation with FEV1 (in % of the predicted value) only in the airway obstruction plus lung hyperinflation group. Conclusions: The FEV1/SVC ratio detected the presence of airway obstruction in more individuals than did the FEV1/FVC ratio; that is, the FEV1/SVC ratio is more reliable than is the FEV1/FVC ratio in the detection of obstructive pulmonary disease.

Keywords: Airway Obstruction; Spirometry; Plethysmography.

Objective: To identify the risk factors for pulmonary complications after thoracotomy for the resection of pulmonary nodules in patients with sarcoma. Methods: A retrospective cohort study involving 68 consecutive patients diagnosed with sarcoma and submitted to a total of 174 thoracotomies for the resection of pulmonary nodules. The dependent variable was defined as the occurrence of any postoperative pulmonary complications. The independent variables were related to the patient, underlying diagnosis, and type of surgical procedure. We analyzed the data using a multivariate generalized estimating equations model with logistic link function and a symmetric correlation structure. Results: Complications were observed in 24 patients (13.8%, 95% CI: 9.0-19.8), and there was one death. The mean length of hospital stay was twice as long in the patients with postoperative complications as in those without (18.8 ± 10.0 days vs. 8.6 ± 6.0 days; p < 0.05). The variables that correlated with the outcome measure were the type of resection (wedge vs. anatomic; OR = 3.6; 95% CI: 1.5-8.8), the need for blood transfusion (OR = 9.8; 95% CI: 1.6-60.1), and the number of nodules resected (OR = 1.1; 95% CI: 1.0-1.1). The multivariate model showed an area under the ROC curve of 0.75 (95% CI: 0.65-0.85). Conclusions: Postoperative pulmonary complications were common after pulmonary nodule resection in patients with sarcoma, occurring in approximately 10% of the procedures. The occurrence of such complications can be expected when techniques other than wedge resection are employed, when blood transfusion is required, and when a great number of nodules are resected. Therefore, it is possible to identify patients at risk for pulmonary complications, who should be closely monitored in the immediate postoperative period. In such patients, all preventive measures should be taken.

Keywords: Sarcoma; Neoplasm metastasis; Risk; Thoracotomy; Thoracic surgery.

Objective: Ventilator-associated pneumonia (VAP) is a serious complication of mechanical ventilation (MV). However, data on VAP in patients on prolonged MV (PMV) are scarce. We aimed to describe the characteristics of VAP patients on PMV and to identify factors associated with mortality. Methods: This was a retrospective cohort study including VAP patients on PMV. We recorded baseline characteristics, as well as 30-day and 90-day mortality rates. Variables associated with mortality were determined by Kaplan-Meier survival analysis and Cox regression model. Results: We identified 80 episodes of VAP in 62 subjects on PMV. The medians for age, Charlson Comorbidity Index, SOFA score, and days on MV were, respectively, 69.5 years, 5, 4, and 56 days. Episodes of VAP occurred between days 21 and 50 of MV in 28 patients (45.2%) and, by day 90 of MV, in 48 patients (77.4%). The 30-day and 90-day mortality rates were 30.0% and 63.7%, respectively. There were associations of 30-day mortality with the SOFA score (hazard ratio [HR] = 1.30; 95% CI: 1.12-1.52; p < 0.001) and use of vasoactive agents (HR = 4.0; 95% CI: 1.2-12.9; p = 0.02), whereas 90-day mortality was associated with age (HR = 1.03; 95% CI: 1.00-1.05; p = 0.003), SOFA score (HR = 1.20; 95% CI: 1.07-1.34; p = 0.001), use of vasoactive agents (HR = 4.07; 95% CI: 1.93-8.55; p < 0.001), and COPD (HR = 3.35; 95% CI: 1.71-6.60; p < 0.001). Conclusions: Mortality rates in VAP patients on PMV are considerably high. The onset of VAP can occur various days after MV initiation. The SOFA score is useful for predicting fatal outcomes. The factors associated with mortality could help guide therapeutic decisions and determine prognosis.

Keywords: Pneumonia, ventilator-associated; Critical care; Ventilators, mechanical.

Objective: To identify factors associated with the minimal clinically important difference (MCID) for health-related quality of life (HRQoL) after physical conditioning in patients with COPD. Methods: Thirty-five patients were submitted to a 12-week program of physical conditioning (strength training plus low-intensity aerobic exercise). Body composition, incremental treadmill test results, endurance treadmill test results, six-minute walk test results, peripheral muscle strength, MIP, baseline dyspnea index (BDI) and Saint George's Respiratory Questionnaire (SGRQ) scores were assessed at baseline and after the program, thus allowing the variations (Δ) to be calculated. The MCID for HRQoL was defined as a reduction of ≥ 4% in the SGRQ total score. Subjects who responded to the program, achieving the MCID for HRQoL, were allocated to the responders (R) group (n = 24), and the remainder were allocated to the non-responders (NR) group (n = 11). Results: The values obtained for the following variables were significantly higher in group R than in group NR (p < 0.05): FEV1 (1.48 ± 0.54 L vs. 1.04 ± 0.34 L); VEF1/FVC (47.9 ± 11.7% vs. 35.5 ± 10.7%); PaO2 (74.1 ± 9.7 mmHg vs. 65.0 ± 8.9 mmHg); and ΔBDI, expressed as median and interquartile range (2.0 [0.0-3.5] vs. 0.0 [0.0-1.0]). The ΔBDI correlated significantly with the ΔSGRQ symptoms domain score, activity domain score and total score (r = 0.44, 0.60 and 0.62, respectively, p < 0.01 for all). After logistic regression, only ΔBDI remained as a predictor of MCID for HRQoL. Conclusions: Achieving the MCID for HRQoL after physical conditioning is associated with dyspnea reduction in COPD patients. Therefore, there is a need to develop treatment strategies designed to interrupt the dyspnea-inactivity-dyspnea cycle in such patients.

Keywords: Pulmonary disease, chronic obstructive; Quality of life; Dyspnea; Exercise; Rehabilitation.

Objective: Post-infectious bronchiolitis obliterans (PIBO) is a clinical entity that has been classified as constrictive, fixed obstruction of the lumen by fibrotic tissue. However, recent studies using impulse oscillometry have reported bronchodilator responses in PIBO patients. The objective of this study was to evaluate bronchodilator responses in pediatric PIBO patients, comparing different criteria to define the response. Methods: We evaluated pediatric patients diagnosed with PIBO and treated at one of two pediatric pulmonology outpatient clinics in the city of Porto Alegre, Brazil. Spirometric parameters were measured in accordance with international recommendations. Results: We included a total of 72 pediatric PIBO patients. The mean pre- and post-bronchodilator values were clearly lower than the reference values for all parameters, especially FEF25‑75%. There were post-bronchodilator improvements. When measured as mean percent increases, FEV1 and FEF25-75%, improved by 11% and 20%, respectively. However, when the absolute values were calculated, the mean FEV1 and FEF25-75% both increased by only 0.1 L. We found that age at viral aggression, a family history of asthma, and allergy had no significant effects on bronchodilator responses. Conclusions: Pediatric patients with PIBO have peripheral airway obstruction that is responsive to treatment but is not completely reversible with a bronchodilator. The concept of PIBO as fixed, irreversible obstruction does not seem to apply to this population. Our data suggest that airway obstruction is variable in PIBO patients, a finding that could have major clinical implications.

Keywords: Bronchiolitis obliterans; Infection/complications; Airway obstruction; Bronchodilator agents.

Objective: To determine the prevalence of and the risk factors for wheezing in infants under one year of age and residing in the city of Porto Alegre, Brazil. Methods: This was a cross-sectional study and is part of a multicenter, multinational project. The parents or legal guardians of the infants were interviewed at primary health care clinics or during home visits. We used a standardized questionnaire, validated for use in Brazil. Potential risk factors were assessed by means of a Poisson regression model with robust variance estimation, using the Wald test to determine the significance of each variable in the model. Results: The sample comprised 1,013 infants. The majority of those were male (53%), and the mean age was 13.5 ± 1.2 months. In 61% of the infants, there had been at least one episode of wheezing, which had recurred at least three times in one third of those infants. The mean age at the first episode of wheezing was 5.16 months (median, 5 months). Over 40% of the infants with wheezing visited emergency rooms due to wheezing, and 17% of those were hospitalized at least once in the first year of life because of this symptom. In the multivariate analysis, the risk factors for wheezing were as follows: male gender; history of pneumonia; maternal smoking during pregnancy; day care center attendance; low maternal level of education; early weaning; multiple episodes of cold; first viral infection prior to 3 months of age; existence of siblings; and history of asthma in the nuclear family. Conclusions: The prevalence of wheezing is high among infants in the city of Porto Alegre. We identified various risk factors for wheezing in infants.

Keywords: Respiratory sounds/epidemiology; Asthma; Infant; Risk factors.

Objective: To determine, in a sample of infants, the prevalence of and risk factors for occasional wheezing (OW) and recurrent wheezing-wheezy baby syndrome (WBS). Methods: Parents of infants (12-15 months of age) completed the International Study of Wheezing in Infants questionnaire. Results: We included 1,269 infants residing in the city of Blumenau, Brazil. Of those, 715 (56.34%) had a history of wheezing, which was more common among boys. The prevalences of OW and WBS were 27.03% (n = 343) and 29.31% (n = 372), respectively. On average, the first wheezing episode occurred at 5.55 ± 2.87 months of age. Among the 715 infants with a history of wheezing, the first episode occurred within the first six months of life in 479 (66.99%), and 372 (52.03%) had had three or more episodes. Factors associated with wheezing in general were pneumonia; oral corticosteroid use; a cold; attending daycare; having a parent with asthma or allergies; mother working outside the home; male gender; no breastfeeding; and mold. Factors associated with WBS were a cold; physician-diagnosed asthma; ER visits; corticosteroid use; pneumonia; bronchitis; dyspnea; attending daycare; bronchodilator use; having a parent with asthma; no breastfeeding; mother working outside the home; and a dog in the household. Conclusions: The prevalence of wheezing in the studied population was high (56.34%). The etiology was multifactorial, and the risk factors were intrinsic and extrinsic (respiratory tract infections, allergies, attending daycare, and early wheezing). The high prevalence and the intrinsic risk factors indicate the need and the opportunity for epidemiological and genetic studies in this population. In addition, mothers should be encouraged to prolong breastfeeding and to keep infants under six months of age out of daycare.

Keywords: Asthma; Prevalence; Risk factors.

Objective: To identify and classify risk factors for venous thromboembolism (VTE) in hospitalized patients, as well as to evaluate medical practices regarding prophylaxis for the disease. Methods: An observational cross-sectional study, carried out between January and March of 2006, involving inpatients at three hospitals in the city of Manaus, Brazil. Risk stratification for VTE was based on the criteria established by the Brazilian Society of Angiology and Vascular Surgery and by the International Union of Angiology. Clinical, surgical and medication-related risk factors were analyzed. The statistical analysis of the data obtained was conducted, adopting an alpha error of 5% and 95% CI. Qualitative data were analyzed using the chi-square test, whereas quantitative data were analyzed using Student's t-test. Results: Of the 1,036 patients included (total number of admissions, 1,051), 515 (49.7%) were male, and 521 (50.3%) were female. A total of 23 risk factors for VTE were identified (total number of occurrences, 2,319). The stratified risk for VTE was 50.6%, 16.6% and 30.8% among the admissions of high-, moderate- and low-risk cases, respectively. In 73.3% of the admissions, nonpharmacological prophylaxis was not employed at any point during the study period. In 74% of those classified as high- or moderate-risk cases, no prophylactic medications were administered. Conclusions: This study showed that, in the population studied, risk factors were common and that prophylactic measures were not employed in patients prone to developing VTE and its complications.

Keywords: Venous thromboembolism; Risk factors; Venous thrombosis/prevention & control.

Objective: To analyze the shuttle walk test, and its respective retest, comparing children with cystic fibrosis (CF) to normal children. Methods: The children were divided into two groups: the CF group, composed of children in whom the diagnosis had been confirmed through sweat testing; and the control group, composed of normal children with no history of pulmonary diseases and no alterations in respiratory function. The children were submitted to at least two consecutive tests, 30 min apart. We evaluated distance walked, cardiac overload, peripheral oxygen saturation (SpO2) and subjective perception of exertion (dyspnea at rest scale and Borg dyspnea scale). Results: A total of 28 children were evaluated. Ages ranged from 7 to 15 years (11.57 ± 2.50 and 11.28 ± 1.85 years for the CF and control groups, respectively). The Borg scale scores were significantly higher in the controls (p = 0.007). No differences were found regarding cardiac overload and SpO2. In relation to the intergroup retest, the controls presented significant improvements on the second test, both in the distance walked and in dyspnea at rest (p = 0.014 and p = 0.036, respectively). The CF group presented a significant improvement only in the dyspnea at rest score (p = 0.168 and p = 0.042, respectively). Conclusion: The cardiac overload imposed by the test did not differ between the groups. The greater fatigue at the beginning of the second test suggests that the 30 min rest between the tests was insufficient.

Keywords: Cystic fibrosis; Exercise test; Heart rate.

Objective: To determine whether a restrictive pattern on spirometry is associated with the level of physical activity in daily life (PADL), as well as with cardiovascular disease (CVD) risk factors, in asymptomatic adults. Methods: A total of 374 participants (mean age, 41 ± 14 years) underwent spirometry, which included the determination of FVC and FEV1. A restrictive pattern on spirometry was defined as an FEV1/FVC ratio > 0.7 and an FVC < 80% of the predicted value. After conducting demographic, anthropometric, and CVD risk assessments, we evaluated body composition, muscle function, and postural balance, as well as performing cardiopulmonary exercise testing and administering the six-minute walk test. The PADL was quantified with a triaxial accelerometer. Results: A restrictive pattern on spirometry was found in 10% of the subjects. After multivariate logistic regression, adjusted for confounders (PADL and cardiorespiratory fitness), the following variables retained significance (OR; 95% CI) as predictors of a restrictive pattern: systemic arterial hypertension (17.5; 1.65-184.8), smoking (11.6; 1.56-87.5), physical inactivity (8.1; 1.43-46.4), larger center-of-pressure area while standing on a force platform (1.34; 1.05-1.71); and dyslipidemia (1.89; 1.12-1.98). Conclusions: A restrictive pattern on spirometry appears to be common in asymptomatic adults. We found that CVD risk factors, especially systemic arterial hypertension, smoking, and physical inactivity, were directly associated with a restrictive pattern, even when the analysis was adjusted for PADL and cardiorespiratory fitness. Longitudinal studies are needed in order to improve understanding of the etiology of a restrictive pattern as well as to aid in the design of preventive strategies.

Keywords: Spirometry; Hypertension; Motor activity; Sedentary lifestyle; Smoking.

Objective: To estimate the total time elapsed between symptom onset and diagnosis of pulmonary tuberculosis (patient delay plus health care system delay), analyzing the factors associated with delayed diagnosis in the state of Rio de Janeiro, Brazil. Methods: We conducted a questionnaire-based survey involving 218 pulmonary tuberculosis patients treated for two months at 20 health care clinics and 3 hospitals in eight cities within the state of Rio de Janeiro. We collected socioeconomic and demographic data, as well as data regarding the health care system and the medical history of the patients. Results: The median time elapsed from the onset of symptoms to diagnosis was 68 days (interquartile range [IQR]: 35-119 days). The median patient delay (time from symptom onset to initial medical visit) was 30 days (IQR: 15-60 days), and the median health care system delay (time from initial medical visit to diagnosis) was 21 days (IQR: 8-47 days). A cut-off point of 21 days was adopted. The factors independently associated with patient delay were female gender, cough, and unemployment [adjusted OR (95% CI) = 2.7 (1.3-5.6); 11.6 (2.3-58.8); and 2.0 (1.0-3.8), respectively], whereas only female gender was independently associated with health care system delay (OR= 3.2; 95% CI: 1.7-6.0). Conclusions: Delayed diagnosis of pulmonary tuberculosis remains a problem in Rio de Janeiro, increasing the risk of transmission and mortality, that risk being greater for women and the socioeconomically disadvantaged. Patients might not recognize the significance of chronic cough as a health problem. Tuberculosis education programs targeting women might improve this situation.

Keywords: Lung neoplasms; Neoplasm metastasis; Antineoplastic combined chemotherapy protocols; Radiotherapy, computer-assisted.

Objective: To determine the risk factors for ER visits due to asthma exacerbations in patients monitored at a referral center. Methods: Prospective cohort study of 253 outpatients (children and adults) with asthma who were monitored for 12 months at the Referral Center of the Program for the Control of Asthma and Allergic Rhinitis in the city of Feira de Santana, Brazil. Results: Exacerbations were common, and 36.5% of the patients sought ER treatment within the twelve-month period. The risk factors for asthma exacerbations were being over 20 years of age (OR = 1.34: (95% CI: 1.06-1.70), residing in an urban area (OR = 1.19; 95% CI: 1.06-1.33); having a low level of education (OR = 1.53: 95% CI: 1.00-2.39); having severe asthma (OR = 1.65; 95% CI: 1.24-2.18); and having chronic rhinitis (OR = 2.20; 95% CI: 1.00-4.80). Conclusions: In this cohort, having chronic rhinitis, having asthma that is more severe and having a low level of education were the main risk factors for ER visits due to asthma exacerbations. These results are similar to those reported for asthma patients who are receiving no regular treatment.

Keywords: Asthma/etiology; Health services; Program evaluation.

Objective: To assess the sensitivity and specificity of flow-volume curves in detecting central airway obstruction (CAO), and to determine whether their quantitative and qualitative criteria are associated with the location, type and degree of obstruction. Methods: Over a four-month period, we consecutively evaluated patients with bronchoscopy indicated. Over a one-week period, all patients underwent clinical evaluation, flow-volume curve, bronchoscopy, and completed a dyspnea scale. Four reviewers, blinded to quantitative and clinical data, and bronchoscopy results, classified the morphology of the curves. A fifth reviewer determined the morphological criteria, as well as the quantitative criteria. Results: We studied 82 patients, 36 (44%) of whom had CAO. The sensitivity and specificity of the flow-volume curves in detecting CAO were, respectively, 88.9% and 91.3% (quantitative criteria) and 30.6% and 93.5% (qualitative criteria). The most prevalent quantitative criteria in our sample were FEF50%/FIF50% ≥ 1, in 83% of patients, and FEV1/PEF ≥ 8 mL . L−1 . min−1, in 36%, both being associated with the type, location, and degree of obstruction (p < 0.05). There was concordance among the reviewers as to the presence of CAO. There is a relationship between the degree of obstruction and dyspnea. Conclusions: The quantitative criteria should always be calculated for flow-volume curves in order to detect CAO, because of the low sensitivity of the qualitative criteria. Both FEF50%/FIF50% ≥ 1 and FEV1/PEF ≥ 8 mL . L−1 . min−1 were associated with the location, type and degree of obstruction.

Keywords: Bronchoscopy; Maximal expiratory flow-volume curves; Sensitivity and specificity; Lung neoplasms.