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.

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 describe the demographic characteristics, everyday habits, socio-economic conditions, clinico-epidemiological profiles and access to health care services among the elderly patients with tuberculosis diagnosed and treated in the city of Recife, Brazil, comparing them to those observed in young adults with tuberculosis. Methods: A case-control type strategy was used to evaluate a cohort of patients with tuberculosis, all of whom were treated in public health care facilities in Recife between May of 2001 and July of 2003. Results: The final cohort consisted of 1127 patients: 136 elderly patients (cases) and 991 young adults (controls). In both groups, males predominated, and the most common form of tuberculosis was the pulmonary form. Alcoholism was more common in the control group, whereas illiteracy was more common in the case group. There were fewer complaints of cough, sweats and chest pain among the patients in the case group than among those in the control group. Serological testing for the human immunodeficiency virus was performed in only 29 patients (2.6%). The percentage of positive sputum smear microscopy results, as well as that of positive cultures, was higher in the controls. Prior to being diagnosed with the disease, patients in both groups had sought treatment at more than two health care facilities and had waited more than two months (after first seeking treatment). The elderly patients presented higher indices of cure and were more often compliant with the treatment regimen, yet presented higher mortality rates. Conclusion: In the population studied, the elderly presented less cough, fewer episodes of night sweats and less chest pain, as well as less often presenting positivity on complementary exams. Nevertheless, the mortality rate was higher among the elderly patients than among the young adult patients. Elderly patients with tuberculosis constitute a population that should be given special attention in public health care facilities.

Keywords: Tuberculosis; Elderly; Case-control; Brazil

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: 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.

Silicosis among pit diggers was first described in 1984. Two years later, a focus of the disease was detected in the region of Ibiapaba, State of Ceará, Brazil. The aims of this study were: 1) to present the educational program to which these workers and their families were submitted; 2) to study, in this population, the impact of the educational program on the knowledge about silicosis and on the behavior changes in the pit digging activity. First, a primary preventing educational intervention (PPEI) was created as per the critical awareness-raising method by Paulo Freire, and applied to this population. Subsequently, the role of PPEI on silicosis control among the pit diggers was studied. In the region there were 1202 pit diggers, and 687 from 5 selected towns were submitted to PPEI. Out of these, 287 workers participated of the second part of the study. All of them were male, ages from 18 to 78 years, 115 were silicotic, 122 non-silicotic, and 46 did not know their health status. Results show that PPEI brought to silicotic and non-silicotic workers a deep knowledge about the relationship between pit digging and silicosis, and induced most of them (85.8%) to quit this activity. PPEI itself promoted an awareness of this population about silicosis, interrupting the epidemiological cycle of the disease in the region of Ibiapaba.

Keywords: Silicosis. Epidemiology. Occupational lung diseases.

Bronchial atresia is a rare, congenital anomaly characterized by the presence of bronchocele with distal hyperinflation. The authors report two cases of segmental bronchial atresia and describe the clinical and roentgenographic findings supporting the diagnosis in the absence of other invasive diagnostic modalities or surgical exploration.

Keywords: pulmonary atresia; bronchi; X-ray computed tomography

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.

We compared the nitrate reductase assay with the proportion method, which is considered the gold standard, in 57 Mycobacterium tuberculosis strains isolated from patients treated at the Federal University of Minas Gerais Hospital das Clínicas, located in the city of Belo Horizonte, Brazil. For rifampin and isoniazid, the sensitivity, specificity, and accuracy of the nitrate reductase assay were all 100%, whereas they were 100%, 88.9%, and 66.7%, respectively, for streptomycin and 98.0%, 100%, and 98.2%, respectively, for ethambutol. The mean time to results was ten days. In the study sample, the nitrate reductase assay proved highly accurate and showed excellent concordance with the gold standard.

Keywords: Mycobacterium tuberculosis; Microbial sensitivity tests; Tuberculosis, multidrug-resistant; Nitrate reductase.

Continuous positive airway pressure (CPAP) is the gold standard for the treatment of obstructive sleep apnea (OSA). Although CPAP was originally applied with a nasal mask, various interfaces are currently available. This study reviews theoretical concepts and questions the premise that all types of interfaces produce similar results. We revised the evidence in the literature about the impact that the type of CPAP interface has on the effectiveness of and adherence to OSA treatment. We searched the PubMed database using the search terms "CPAP", "mask", and "obstructive sleep apnea". Although we identified 91 studies, only 12 described the impact of the type of CPAP interface on treatment effectiveness (n = 6) or adherence (n = 6). Despite conflicting results, we found no consistent evidence that nasal pillows and oral masks alter OSA treatment effectiveness or adherence. In contrast, most studies showed that oronasal masks are less effective and are more often associated with lower adherence and higher CPAP abandonment than are nasal masks. We concluded that oronasal masks can compromise CPAP OSA treatment adherence and effectiveness. Further studies are needed in order to understand the exact mechanisms involved in this effect.

Keywords: Sleep apnea, obstructive; Continuous positive airway pressure; Masks.

Objective: To evaluate the accuracy of rapid molecular testing as a diagnostic tool and estimate the incidence of smear-positive pulmonary tuberculosis among the indigenous population. Methods: This is an epidemiological study based on secondary data. We calculated the incidence of smear-positive pulmonary tuberculosis between January 1st, 2011 and December 31, 2016, and the performance of bacilloscopy and rapid molecular testing in diagnosing pulmonary tuberculosis compared to sputum culture (standard test). Results: We included 4,048 cases of indigenous people with respiratory symptoms who provided sputum samples for analysis. Among them, 3.7%, 6.7%, and 3.7% had positive results for bacilloscopy, sputum culture, and rapid molecular testing, respectively. The mean incidence of pulmonary tuberculosis was 269.3/100 thousand inhabitants. Rapid molecular testing had 93.1% sensitivity and 98.2% specificity, compared to sputum culture. Bacilloscopy showed 55.1% sensitivity and 99.6% specificity. Conclusions: Rapid molecular testing can be useful in remote areas with limited resources and a high incidence of tuberculosis, such as indigenous villages in rural regions of Brazil. In addition, the main advantages of rapid molecular testing are its easy handling, fast results, and the possibility of detecting rifampicin resistance. Together, these attributes enable the early start of treatment, contributing to reduce the transmission in communities recognized as vulnerable to infection and disease.

Keywords: Tuberculosis; Molecular diagnostic testing; Diagnostic tests, routine; Indians, South American.

Objective: Virulent strains of the Mycobacterium tuberculosis complex, under certain appropriate conditions, grow as characteristic ropes, bundles or serpentine cords known as cord factor or growth in cords. The objective of the present study was to evaluate cord factor detection as a method of achieving presumptive identification of the M. tuberculosis complex, comparing it to conventional typing tests. Methods: A total of 743 strains were analyzed from January of 2002 to December of 2005 in the Mycobacteria Sector of the Adolfo Lutz Institute, located in the city of Santos, Brazil. Samples were obtained from clinical specimens collected from patients with respiratory symptoms treated at basic health clinics in the greater metropolitan area of Santos. Ziehl-Neelsen-stained smears were prepared, 301 (40.5%) in MB/BacT broth and 442 (59.5%) on solid media, either Lowenstein-Jensen or Ogawa-Kudoh. Results: The sensitivity, specificity, positive predictive value and negative predictive value obtained during the performance comparison of the two methods (cord factor detection and conventional typing) using both isolation media were, respectively, 98.5, 88, 97 and 93%. The method was more sensitive on solid medium (100%), and the difference in sensitivity between the two media types was only 2.7%. Conclusions: Taking into consideration the results obtained, we conclude that, in laboratories with a high incidence of M. tuberculosis complex isolation and limited economic resources, cord factor detection is a fast and valid criterion for identifying these mycobacteria using liquid or solid medium. It also enables subsequent conclusive identification tests, as well as additional sensitivity tests when necessary.

Keywords: Laboratory techniques and procedures; Mycobacterium tuberculosis; Cord factors

Objective: To determine the role of the IL8 rs4073 polymorphism in predicting the risk of central nervous system (CNS) toxicity in patients receiving standard pharmacological treatment for multidrug-resistant tuberculosis (MDR-TB). Methods: A cohort of 85 consenting MDR-TB patients receiving treatment with second-line antituberculosis drugs had their blood samples amplified for the IL8 (rs4073) gene and genotyped. All patients were clinically screened for evidence of treatment toxicity and categorized accordingly. Crude and adjusted associations were assessed. Results: The chief complaints fell into the following categories: CNS toxicity; gastrointestinal toxicity; skin toxicity; and eye and ear toxicities. Symptoms of gastrointestinal toxicity were reported by 59% of the patients, and symptoms of CNS toxicity were reported by 42.7%. With regard to the genotypes of IL8 (rs4073), the following were identified: AA, in 64 of the study participants; AT, in 7; and TT, in 11. A significant association was found between the dominant model of inheritance and CNS toxicity for the crude model (p = 0.024; OR = 3.57; 95% CI, 1.18-10.76) and the adjusted model (p = 0.031; OR = 3.92; 95% CI, 1.13-13.58). The AT+TT genotype of IL8 (rs4073) showed a 3.92 times increased risk of CNS toxicity when compared with the AA genotype. Conclusions: The AT+TT genotype has a tendency to be associated with an increased risk of adverse clinical features during MDR-TB treatment.

Keywords: Tuberculosis, multidrug-resistant; Immunity; Pharmacogenetics; Polymerase chain reaction; Risk.

Objective: To evaluate the treatment compliance of patients with paracoccidioidomycosis. Methods: We studied 188 patients with paracoccidioidomycosis admitted to a tertiary referral hospital in the Central-West Region of Brazil from 2000 to 2010, to assess their compliance to treatment. In order to be considered compliant, patients needed to present two established criteria: (1) receive medicines from the pharmacy, and (2) achieve a self-reported utilization of at least 80% of the dispensed antifungal compounds prescribed since their previous appointment. Results: Most patients were male (95.7%), had the chronic form of the disease (94.2%), and were treated with cotrimoxazole (86.2%). Only 44.6% of patients were treatment compliant. The highest loss to follow-up was observed in the first 4 months of treatment (p < 0.02). Treatment compliance was higher for patients with than for those without pulmonary involvement (OR: 2.986; 95%CI 1.351-6.599), and higher for patients with than without tuberculosis as co-morbidity (OR: 2.763; 95%CI 1.004-7.604). Conclusions: Compliance to paracoccidioidomycosis treatment was low, and the period with the highest loss to follow-up corresponds to the first four months. Pulmonary paracoccidioidal involvement or tuberculosis comorbidity predicts a higher compliance to paracoccidioidomycosis therapy.

Keywords: Paracoccidioidomycosis; Treatment adherence and compliance; loss to follow-up; mycoses

Background: The relationship between asthma and gastroesophageal reflux is, as yet, not completely understood. Among the mechanisms thought to be responsible for gastroesophageal reflux-related worsening of asthma symptoms are the vagovagal reflex and microaspiration. Objective: To assess forced expiratory volume in one second after acid infusion. Method: This study investigated the effect of acid infusion in 13 volunteers with moderate asthma and gastroesophageal reflux. Spirometry was performed before and after insertion of an 8F nasogastric tube and a pH meter. After 15 minutes of saline solution infusion into the midpoint between the upper esophageal sphincter and lower esophageal sphincter, and again after 15 minutes of esophageal acidification (with hydrochloric acid) of the same area, forced expiratory volume in one second was reassessed. Acidification was repeated every 5 minutes until forced expiratory volume in one second values stabilized (variation: < 5%). Results: Mean forced expiratory volume in one second values remained stable during the tube insertion, saline infusion, initial hydrochloric acid infusion and subsequent hydrochloric acid infusion procedures (p = 0.72). Lower forced expiratory volume in one second values were seen resulting from the tube insertion in two patients (drops of 11% and 22%, respectively), after saline infusion in another two (drops of 13% and 14%) and after acid infusion in 1 (a drop of 22%). Conclusion: Esophageal acidification over short periods does not lead to spirometric alterations in a group of asthmatics with gastroesophageal reflux. However, in some cases, simple esophageal procedures or infusions result in bronchospasm.

Keywords: Key words: Asthma. Gastroesophageal reflux. Respiratory function tests. Endoscopy/methods.

Objective: To evaluate the impact that Family Health Program (FHP) team training and active surveillance have on the detection of TB cases in a low-income community in the city of Fortaleza, Brazil. Methods: The study was performed in an area with approximately 25,000 inhabitants, served by a health care center with five FHP teams, in the city of Fortaleza, Brazil. Although all of the teams were trained, active surveillance was carried out only in one of the areas (area 5). We compared the number of TB cases detected in each of the five areas prior to and after the intervention. We also compared the number of TB cases detected in area 5 to the number of those detected in the other areas, as well as to the citywide number of reported TB cases in Fortaleza, within the same period. Results: The number of TB cases detected in the area studied increased from 1 in 2002 to 22 in 2004 (p < 0.05). There was no significant difference between the number of TB cases in area 5 and that observed for each of the other four areas (p > 0.05). There was a significant increase in the number of TB cases detected in the area studied when compared to the city as a whole (p < 0.05). Conclusions: Training and sensitization of FHP professionals were effective in promoting an increase in the number of TB cases detected in a low-income community.

Keywords: Tuberculosis; Communicable disease control; Family health program; Epidemiologic surveillance.

Background: The diagnosis of pleural tuberculosis continues to be a challenge due to the low sensitivity of traditional diagnostic methods. Histopathological examination of pleural tissue is the most accurate method, with a sensitivity of up to 80%. Determination of adenosine deaminase levels is a recently introduced method, although its usefulness in the diagnosis of pleural tuberculosis in Brazil has yet to better elucidated. Objective: To verify the sensitivity and specificity of an experimental method of measuring adenosine deaminase activity in pleural fluid in a series of patients with pleural effusion patients evaluated between August 1998 and November 2002 in Rio de Janeiro (RJ). Results: Out of 137 cases, 111 pleural fluid samples were available. Of those, 83 were from pleural tuberculosis patients. Among the 67 pleural tuberculosis patients tested, 10 (14.9%) presented human immunodeficiency virus. The adenosine deaminase cutoff value of 35U/L was determined by a receiver operator characteristic curve. The sensitivity, specificity and likelihood ratios (positive and negative) were 92.8%, 93.3%, 25.8 and 13.9, respectively. Mean adenosine deaminase in the pleural tuberculosis group was 84.7 ± 43.1 U/L, versus 15.9 ± 11.1 U/L in the group with other diseases. There was no significant difference in adenosine deaminase activity between patients with and without human immunodeficiency virus co-infection. Conclusions: Adenosine deaminase measurement in pleural fluid is a sensitive and specific method for the diagnosis of pleural tuberculosis and its use can preclude the need for pleural biopsy in the initial workup of pleural effusion patients. An adenosine deaminase cutoff value of 35U/L is recommended.

Keywords: Pleural fluid. Adenosine deaminase. Diagnosis. Tuberculosis. HIV

Objective: To investigate the detection of subsolid nodules (SSNs) on chest CT scans of outpatients before and during the COVID-19 pandemic, as well as to correlate the imaging findings with epidemiological data. We hypothesized that (pre)malignant nonsolid nodules were underdiagnosed during the COVID-19 pandemic because of an overlap of imaging findings between SSNs and COVID-19 pneumonia. Methods: This was a retrospective study including all chest CT scans performed in adult outpatients (> 18 years of age) in September of 2019 (i.e., before the COVID-19 pandemic) and in September of 2020 (i.e., during the COVID-19 pandemic). The images were reviewed by a thoracic radiologist, and epidemiological data were collected from patient-filled questionnaires and clinical referrals. Regression models were used in order to control for confounding factors. Results: A total of 650 and 760 chest CT scans were reviewed for the 2019 and 2020 samples, respectively. SSNs were found in 10.6% of the patients in the 2019 sample and in 7.9% of those in the 2020 sample (p = 0.10). Multiple SSNs were found in 23 and 11 of the patients in the 2019 and 2020 samples, respectively. Women constituted the majority of the study population. The mean age was 62.8 ± 14.8 years in the 2019 sample and 59.5 ± 15.1 years in the 2020 sample (p < 0.01). COVID-19 accounted for 24% of all referrals for CT examination in 2020. Conclusions: Fewer SSNs were detected on chest CT scans of outpatients during the COVID-19 pandemic than before the pandemic, although the difference was not significant. In addition to COVID-19, the major difference between the 2019 and 2020 samples was the younger age in the 2020 sample. We can assume that fewer SSNs will be detected in a population with a higher proportion of COVID-19 suspicion or diagnosis.

Keywords: Solitary pulmonary nodule; Multiple pulmonary nodules; Lung neoplasms/diagnostic imaging; Tomography, X-ray computed; COVID-19.