1. Pulmonary Function Laboratory and Respiratory Investigation Unit, Division of Respirology, Kingston Health Science Center & Queen’s University, Kingston (ON) Canada. 2. Unidade de Fisiologia Pulmonar, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre (RS) Brasil.

Objective: To investigate the validity of field walking tests to identify exercise-induced hypoxemia and to compare cardiorespiratory responses and perceived effort between laboratory-based and field-based exercise tests in subjects with bronchiectasis. Methods: This was a cross-sectional study involving 72 non-oxygen-dependent participants (28 men; mean age = 48.3 ± 14.5 years; and mean FEV1 = 54.1 ± 23.4% of the predicted value). The participants underwent cardiopulmonary exercise testing (CPET) on a treadmill and constant work-rate exercise testing (CWRET) on the same day (1 h apart). In another visit, they underwent incremental shuttle walk testing (ISWT) and endurance shuttle walk testing (ESWT; 1 h apart). Desaturation was defined as a reduction in SpO2 ≥ 4% from rest to peak exercise. Results: CPET results were compared with ISWT results, as were CWRET results with ESWT results. There was no difference in the magnitude of desaturation between CPET and ISWT (−7.7 ± 6.3% vs. −6.6 ± 5.6%; p = 0.10) and between CWRET and ESWT (−6.8 ± 5.8% vs. −7.2 ± 6.3%; p = 0.50). The incremental tests showed an agreement in the magnitude of desaturation in the desaturation and no desaturation groups (42 and 14 participants, respectively; p < 0.01), as did the endurance tests (39 and 16 participants; p < 0.01). The magnitude of desaturation was similar among the participants who did or did not reach at least 85% of the maximum predicted HR. Conclusions: Field exercise tests showed good precision to detect desaturation. Field tests might be an alternative to laboratory tests when the clinical question is to investigate exercise-induced desaturation in subjects with bronchiectasis.

Keywords: Bronchiectasis; Oxygen; Hypoxia; Exercise test.

Objective: To describe causes of death and mortality data related to cystic fibrosis (CF) using a multiple-cause-of-death methodology. Methods: Annual mortality data for the 1999-2017 period were extracted from the Brazilian National Ministry of Health Mortality Database. All death certificates in which category E84 (CF) of the ICD-10, was listed as an underlying or associated cause of death were selected. Epidemiological and clinical data were described, and standardized mortality rates were calculated per year and for the 2000-2017 period. A joinpoint regression analysis was performed to detect changes in the mortality rates during the study period. Results: Overall, 2,854 CF-related deaths were identified during the study period, ranging from 68 in 1999 to 289 in 2017. CF was the underlying cause of death in 83.5% of the death certificates. A continuous upward trend in the death rates was observed, with a significant annual percent change of 6.84% (5.3-8.4%) among males and 7.50% (6.6-8.4%) among females. The median age at death increased from 7.5 years in 1999 to 56.5 years in 2017. Diseases of the respiratory system accounted for 77% of the associated causes in the death certificates that reported CF as the underlying cause of death. Conclusions: A significant and continuous increase in CF-related death rates was found in Brazil in the last years, as well as a concurrent increase in the median age at death.

Keywords: Cystic fibrosis/mortality; Cause of death; Death certificates; Brazil.

Objective: To describe the implementation of a Tele-ICU program during the COVID-19 pandemic, as well as to describe and analyze the results of the first four months of operation of the program. Methods: This was a descriptive observational study of the implementation of a Tele-ICU program, followed by a retrospective analysis of clinical data of patients with COVID-19 admitted to ICUs between April and July of 2020. Results: The Tele-ICU program was implemented over a four-week period and proved to be feasible during the pandemic. Participants were trained remotely, and the program had an evidence-based design, the objective being to standardize care for patients with COVID-19. More than 100,000 views were recorded on the free online platforms and the mobile application. During the study period, the cases of 326 patients with COVID-19 were evaluated through the program. The median age was 60 years (IQR, 49-68 years). There was a predominance of males (56%). There was also a high prevalence of hypertension (49.1%) and diabetes mellitus (38.4%). At ICU admission, 83.7% of patients were on invasive mechanical ventilation, with a median PaO2/FiO2 ratio < 150. It was possible to use lung-protective ventilation in 75% of the patients. Overall, in-hospital mortality was 68%, and ICU mortality was 65%. Conclusions: Our Tele-ICU program provided multidisciplinary training to health care professionals and clinical follow-up for hundreds of critically ill patients. This public health care network initiative was unprecedented and proved to be feasible during the COVID-19 pandemic, encouraging the creation of similar projects that combine evidence-based practices, training, and Tele-ICU.

Keywords: Telemedicine; Critical care; Coronavirus infections; Patient care management.

Objective: Evaluation of enlarged mediastinal lymph nodes is crucial for patient management. Malignant lymphoma and sarcoidosis are often difficult to differentiate. Our objective was to determine the diagnostic accuracy of MRI for differentiating between sarcoidosis and malignant lymphoma. Methods: This was a retrospective study involving 47 patients who underwent chest MRI and were diagnosed with one of the diseases between 2017 and 2019. T1, T2, and diffusion-weighted signal intensity were measured. Apparent diffusion coefficients (ADCs) and T2 ratios were calculated. The diagnostic performance of MRI was determined by ROC analysis. Results: Mean T2 ratio was significantly lower in the sarcoidosis group than in the lymphoma group (p = 0.009). The T2-ratio cutoff value that best differentiated between lymphoma-related and sarcoidosis-related enlarged lymph nodes was 7.1, with a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 58.3%, 95.6%, 76.5%, 93.3%, and 68.7%, respectively. The mean ADC was significantly lower in the lymphoma group than in the sarcoidosis group (p = 0.002). The ADC cutoff value that best differentiated between lymphoma-related and sarcoidosis-related enlarged lymph nodes was 1.205, with a sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 87.5%, 82.6%, 85.1%, 84.0% and 86.3%, respectively. No significant differences were found between the two groups regarding T1 signal intensity, T2 signal intensity, and lymph node diameter. Conclusions: MRI parameters such as ADC, diffusion, and T2 ratio can be useful in the differentiation between sarcoidosis and lymphoma in the evaluation of enlarged lymph nodes.

Keywords: Diffusion magnetic resonance imaging; Lymphoma; Lymph nodes; Sarcoidosis.

Objective: To identify the determinants of tuberculosis-related variables in the various regions of Brazil and evaluate trends in those variables over the ten-year period preceding the end of the timeframe defined for the United Nations Millennium Development Goals (MDGs). Methods: This was an ecological analytical study in which we utilized eight national public databases to investigate the 716,971 new tuberculosis cases reported between 2006 and 2015. Results: Over the study period, there were slight reductions in the prevalence, incidence, and mortality associated with tuberculosis. Brazil did not reach the MDG for tuberculosis-related mortality. Among the performance indicators of tuberculosis control, there were improvements only in those related to treatment and treatment abandonment. In terms of the magnitude of tuberculosis, substantial regional differences were observed. The tuberculosis incidence rate was highest in the northern region, as were the annual mean temperature and relative air humidity. That region also had the second lowest human development index, primary health care (PHC) coverage, and number of hospitalizations for tuberculosis. The northeastern region had the highest PHC coverage, number of hospitalizations for primary care-sensitive conditions, and tuberculosis-related mortality rate. The southern region showed the smallest reductions in epidemiological indicators, together with the greatest increases in the frequency of treatment abandonment and retreatment. The central-west region showed the lowest overall magnitude of tuberculosis and better monitoring indicators. Conclusions: The situation related to tuberculosis differs among the five regions of Brazil. Those differences can make it difficult to control the disease in the country and could explain the fact that Brazil failed to reach the MDG for tuberculosis-related mortality. Tuberculosis control measures should be adapted to account for regional differences.

Keywords: Tuberculosis/epidemiology; Tuberculosis, pulmonary/epidemiology; Health status indicators; Social determinants of health; Healthcare disparities.

Objective: To evaluate the accuracy of determining the adenosine deaminase (ADA) level, the 2'-deoxyadenosine/ADA ratio, and the LDH/ADA ratio in pleural fluid for the diagnosis of pleural tuberculosis (PT) in children and adolescents. Methods: This was a retrospective cross-sectional study conducted at a tertiary hospital in a high-tuberculosis-incidence area, between 2001 and 2018. All patients with ADA in pleural fluid and a confirmed diagnosis of PT (cPT) or parapneumonic effusion (PPE) were included. Results: The cPT and PPE groups comprised 25 and 68 individuals, respectively. At a cutoff of 40 U/L, ADA measurement showed the following: sensitivity, 88%; specificity, 31%; positive predictive value (PPV), 32%; negative predictive value (NPV), 88%; and overall accuracy, 46%. The best cutoffs were an ADA level of 125 U/L, a 2'-deoxyadenosine/ADA ratio of 0.5, and an LDH/ADA ratio of 8.3, with AUC of 0.67, 0.75, and 0.82, respectively. The sensitivity, specificity, PPV, NPV, and overall accuracy of the 125 U/L ADA cutoff were 84%, 65%, 47%, 92%, and 70%, respectively, compared with 79%, 79%, 59%, 91%, and 79%, respectively, for the 8.3 LDH/ADA ratio cutoff. Changing the LDH/ADA ratio cutoff to 3.0 increased the specificity to 98%. Conclusions: The ADA level and the 2'-deoxyadenosine/ADA ratio are not good biomarkers for the diagnosis of PT in pediatric patients. Determination of the LDH/ADA ratio provides the best overall accuracy for the diagnosis of PT in such patients.

Keywords: Adenosine deaminase; Pleural effusion; Tuberculosis, pleural/diagnosis; Child; Adolescent.

Objective: Although Mycobacterium avium complex (MAC) lung disease has been shown to be associated with lung cancer and hematologic malignancies, there have been few studies of its relationships with other types of cancer. The aim of this study was to assess the effect that coexisting advanced extrapulmonary solid tumors have on the progression of MAC lung disease. Methods: This was a retrospective study of patients diagnosed with MAC lung disease, on the basis of the American Thoracic Society (ATS) criteria, between October of 2005 and March of 2019. The patients were divided into three groups: those with advanced-stage cancer (A-SC group); those with early-stage cancer (E-SC group); and those without cancer (control group). Progression of MAC lung disease was defined as exacerbation seen on imaging. Patient characteristics and the time to progression were compared among the three groups. Results: A total of 286 patients met the ATS diagnostic criteria for MAC lung disease, and 128 of those were excluded. Of the remaining 158 patients, 20 (7.0%) were in the A-SC group, 36 (12.6%) were in the E-SC group, and 102 (35.7%) were in the control group. The median time to progression in the A-SC, E-SC, and control groups was 432, 3,595, and 2,829 days, respectively (p < 0.01). A proportional hazards model showed that the significant predictors of MAC lung disease progression were advanced-stage cancer (hazard ratio [HR] = 6.096; 95% CI: 2.688-13.826; p < 0.01), cavitary lesions (HR = 2.750; 95% CI: 1.306-5.791; p < 0.01), and a high Nodule-Infiltration-Cavity-Ectasis score (HR = 1.046; 95% CI: 1.004-1.091; p = 0.033). Conclusions: A coexisting advanced extrapulmonary solid tumor could hasten the progression of MAC lung disease.

Keywords: Nontuberculous mycobacteria; Mycobacterium avium complex; Neoplasms; Radiography.

Objective: To assess the diagnostic performance of the Xpert MTB/RIF assay, a rapid molecular test for tuberculosis, comparing it with that of AFB staining and culture, in BAL fluid (BALF) samples from patients with clinically suspected pulmonary tuberculosis (PTB) who are sputum smear-negative or produce sputum samples of insufficient quantity. Methods: This was a retrospective study of 140 cases of suspected PTB in patients who were smear-negative or produced insufficient sputum samples and were evaluated at a tertiary teaching hospital in the city of Rio de Janeiro, Brazil. All of the patients underwent fiberoptic bronchoscopy with BAL. The BALF specimens were evaluated by AFB staining, mycobacterial culture, and the Xpert MTB/RIF assay. Results: Among the 140 patients, results for all three microbiological examinations were available for 73 (52.1%), of whom 22 tested positive on culture, 17 tested positive on AFB staining, and 20 tested positive on the Xpert MTB/RIF assay. The sensitivity, specificity, positive predictive value, negative predictive value, and overall accuracy for AFB staining were 68.1%, 96.1%, 88.2%, 87.5%, and 87.6%, respectively, compared with 81.8%, 96.1%, 90.0%, 92.4%, and 91.8%, respectively, for the Xpert MTB/RIF assay. The agreement between AFB staining and culture was 82.3% (kappa = 0.46; p < 0.0001), whereas that between the Xpert MTB/RIF assay and culture was 91.8% (kappa = 0.8; p < 0.0001). Conclusions: In BALF samples, the Xpert MTB/RIF assay performs better than do traditional methods, providing a reliable alternative to sputum analysis in suspected cases of PTB. However, the rate of discordant results merits careful consideration.

Keywords: Tuberculosis; Molecular diagnostic techniques; Bronchoscopy; Bronchoalveolar lavage fluid; Mycobacterium tuberculosis.

Tuberculosis remains a major public health problem deeply influenced by inequality. The present study used data from the Brazilian Tuberculosis Case Registry Database in order to compare the rates of tuberculosis treatment success, loss to follow-up, and tuberculosis mortality between the homeless population and the general population of Brazil. The likelihood of tuberculosis treatment success was reduced by approximately 50% in the homeless population. In addition, the rate of loss to follow-up was 2.9 times higher in the homeless population than in the general population, and the rate of tuberculosis mortality was 2.5 times higher in the former.

Keywords: Tuberculosis; Homeless persons; Health information systems; Health policy.

Early, accurate diagnosis of tuberculosis is one of the major pillars of the control of the disease. The purpose of this consensus statement is to provide health professionals with the most current, useful evidence for the diagnosis of tuberculosis in Brazil. To that end, the Tuberculosis Committee of the Brazilian Thoracic Association brought together 14 members of the Association with recognized expertise in tuberculosis in Brazil to compose the statement. A nonsystematic review of the following topics was carried out: clinical diagnosis, bacteriological diagnosis, radiological diagnosis, histopathological diagnosis, diagnosis of tuberculosis in children, and diagnosis of latent tuberculosis infection.

Keywords: Tuberculosis/diagnosis; Mycobacterium tuberculosis; Tuberculosis, multidrug-resistant/diagnosis; Latent tuberculosis/diagnosis.

On April 1st, 2020, COVID-19 surpassed tuberculosis regarding the number of deaths per day worldwide. The combination of tuberculosis and COVID-19 has great potential for morbidity and mortality. In addition, the COVID-19 pandemic has had a significant impact on the diagnosis and treatment of tuberculosis. In this review article, we address concurrent tuberculosis and COVID-19, with particular regard to the differences between Brazil and Europe. In addition, we discuss priorities in clinical care, public health, and research.

Keywords: Tuberculosis; COVID-19; SARS-CoV-2; Coronavirus.