This is a prospective study of benign and malignant pleural effusions carried out to determine the diagnostic yield of standard cytopathology compared to findings of DNA ploidy obtained by flow cytometry. Twenty-six samples of pleural effusion obtained by thoracocentesis were analyzed by cytopathology and flow cytometry. Final diagnosis was confirmed in all instances by histopathology of pleural biopsies. Ten samples were excluded from the analysis due to technical reasons, and the remaining 16 were used in the study. There were 13 malignant and 3 benign pleural effusions. Cytopathology revealed 9 malignant effusions and 7 benign effusions (4 false negatives). Flow cytometry findings have shown euploid DNA content in all 3 benign effusions (positive predictive value and specificity of 100%) and in 8 malignant effusions (positive value and specificity of 100%) and in 8 malignant effusions (sensitivity of 38.4% and negative predictive value of 27.2%). Cytopathology showed specificity of 100%, sensitivity of 69.2%, and positive and negative predictive values of 100% and 42.8%, respectively. The authors concluded that in this study the low sensitivity and negative value of flow cytometry in comparison to conventional cytopathology have limited the usefulness of flow cytometry to the finding of euploid DNA contents in benign pleural effusions.

Keywords: Flow cytometry. Cytopathology. DNA ploidy. Pleural effusion.

Objective: To establish the accuracy of frozen section examination in identifying tumor spread through air spaces (STAS), as well as to propose a reproducible technical methodology for frozen section analysis. We also aim to propose a method to be incorporated into the decision making about the need for conversion to lobectomy during sublobar resection. Methods: This was a nonrandomized prospective study of 38 patients with lung cancer who underwent surgical resection. The findings regarding STAS in the frozen section were compared with the definitive histopathological study of paraffin-embedded sections. We calculated a confusion matrix to obtain the positive predictive value (PPV), negative predictive value (NPV), sensitivity, specificity and accuracy. Results: The intraoperative frozen section analysis identified 7 STAS-positive cases that were also positive in the histopathological examination, as well as 3 STAS-negative cases that were positive in the in the histopathological examination. Therefore, frozen section analysis was determined to have a sensitivity of 70%, specificity of 100%, PPV of 100%, NPV of 90.3%, and accuracy of 92% for identifying STAS. Conclusions: Frozen section analysis is capable of identifying STAS during resection in patients with lung cancer. The PPV, NPV, sensitivity, and specificity showed that the technique proposed could be incorporated at other centers and would allow advances directly linked to prognosis. In addition, given the high accuracy of the technique, it could inform intraoperative decisions regarding sublobar versus lobar resection.

Keywords: Neoplasm invasiveness; Frozen sections; Lung neoplasms/pathology; Lung neoplasms/surgery.

A significant percentage of pleural effusions remains without a diagnostic explanation. In such circumstances, the anatomical-pathological result of nonspecific chronic pleuritis should be revised. This is an important issue, not only for the pathologist, but mainly for the pneumologist, who usually makes the clinical-pathological correlation during the routine practice. Although the existence of established criteria is accepted, they are certainly subjective and make the communication by means of a common language difficult, mainly among pathologists. The authors recently studied 311 pleural biopsies with histo-pathological diagnoses of chronic nonspecific pleuritis. All specimens were reviewed and the histo-pathological parameters quantified by stereology. The patients were stratified according to the final diagnosis of their disease, including cases of chronic renal failure, vasculitis, pancreatitis, tuberculosis, cancer, and congestive cardiac failure, in this case considering the pleura as normal. This procedure allowed us to obtain a discriminating model, whose morphological subcriteria classified almost 90% of the nonspecific chronic pleuritis biopsies, according to their final clinical diagnoses, which included true nonspecific chronic pleuritis or tuberculosis pleuritis, paraneoplastic pleuritis, or even normal pleura. By adding to this model the biochemistry or differential cytology of the pleural liquid, its classificatory power reaches 99% of correctness. This study represents the result of the experience acquired over several years in the histo-pathological interpretation of pleural biopsies, based on the correlation between morphology and biochemistry and cytology of the pleural fluid.

Keywords: Biopsy, needle. Pleura/pathology. Pleura/cytology. Pleural effusion.

Objective: To describe clinical and laboratory characteristics in patients with tuberculosis-related or lymphoma-related lymphocytic pleural effusions, in order to identify the variables that might contribute to differentiating between these diseases. Methods: This was a retrospective study involving 159 adult HIV-negative patients with tuberculosis-related or lymphoma-related lymphocytic effusions (130 and 29 patients, respectively), treated between October of 2008 and March of 2010 at the Pleural Diseases Outpatient Clinic of the University of São Paulo School of Medicine Hospital das Clínicas Heart Institute, in the city of São Paulo, Brazil. Results: Mean age and the mean duration of symptoms were lower in the tuberculosis group than in the lymphoma group. The levels of proteins, albumin, cholesterol, amylase, and adenosine deaminase (ADA) in pleural fluid, as well as the serum levels of proteins, albumin, and amylase, were higher in the tuberculosis group, whereas serum cholesterol and triglycerides were higher in the lymphoma group. Pleural fluid leukocyte and lymphocyte counts were higher in the tuberculosis group. Of the tuberculosis group patients, none showed malignant cells; however, 4 showed atypical lymphocytes. Among the lymphoma group patients, cytology for neoplastic cells was positive, suspicious, and negative in 51.8%, 24.1%, and 24.1%, respectively. Immunophenotyping of pleural fluid was conclusive in most of the lymphoma patients. Conclusions: Our results demonstrate clinical and laboratory similarities among the patients with tuberculosis or lymphoma. Although protein and ADA levels in pleural fluid tended to be higher in the tuberculosis group than in the lymphoma group, even these variables showed an overlap. However, none of the tuberculosis group patients had pleural fluid ADA levels below the 40-U/L cut-off point.

Keywords: Pleural effusion; Tuberculosis; Lymphoma; Adenosine deaminase; Diagnosis, differential.

The clinical-radiographic presentation and tuberculosis prediction in patients that have undergone dry pleural biopsy, as well as its usefulness and complications, have been evaluated in this retrospective study, conducted in the Octávio Mangabeira Hospital (Salvador, Bahia, Brazil), where 107 patients consecutively submitted to this exam have been analyzed. Altogether 108 biopsies have been performed using Cope's needle (biopsies of both hemithoraxes were performed in one patient). The following diagnoses were obtained: a) tuberculosis (n = 66); b) probable tuberculosis (n = 4); c) neoplasm (n = 2); d) parapneumonic (n = 3), and e) not determined (32). Sixty-seven (62.6%) of the patients were male, and mean age was 34.5 ± 15.4 years. Analyses carried out compare patients diagnosed with tuberculosis (whether confirmed or probable) to those with different diagnoses (miscellaneous). Tuberculosis patients were younger (p < 0.01), expectoration was less frequent (p < 0.01), previous tuberculosis was less often reported (p = 0.04) and PPD reactivity was more frequent (p < 0.01). No significant differences were found between the two groups as to the extent of pleural commitment and its variation in the period observed. Presence of acinar infiltrations in the upper lobes was correlated with tuberculosis diagnosis in the 13 patients in which this feature was observed. Pleural fragments were present in 100 out of 108 cases (92.6%) and the diagnosis was made in the first biopsy in 64 out of 108 cases (59.3%). Ten minor complications have occurred (9.3%) in the 108 biopsies: 6 bloody sputums, 3 small pneumothoraxes, and one moderate subcutaneous emphysema. The authors conclude that for the various predictive indicators of tuberculosis analyzed, except for the presence of acinar infiltrations in the upper lobes, there is broad overlap between the two groups compared, meaning that a safe clinical diagnosis cannot be provided and thus reinforcing the need of performing biopsies. Dry pleural biopsy offers a satisfactory diagnostic yield in areas with high prevalence of tuberculosis and proved safe, when performed by experienced personnel.

Keywords: Pleural tuberculosis. Pleural thickening. Pleural biopsy. Diagnosis.

Objective: To evaluate the efficacy of mitomycin C (MMC) in the endoscopic treatment of tracheal stenosis. Methods: Patients with laryngotracheal, tracheal, or tracheobronchial stenosis were treated with dilation and topical MMC. The inclusion criteria were as follows: being ineligible for surgery (for medical reasons) at the time of evaluation; membranous stenosis responding well to dilation; and postoperative stenosis at the anastomosis site. Etiology of stenosis and indication for treatment with MMC, as well as site, length, and percentage of stenosis, together with presence of tracheostomy and duration of follow-up, were analyzed. The outcomes evaluated were symptom-free interval ≥ 12 months, number of dilations with topical application of MMC, and complications. Results: Twenty-two patients (15 men and 7 women) were treated between 2003 and 2010. Stenosis was due to endotracheal intubation in 15 patients and surgery in 8. Pure tracheal stenosis was encountered in 13 patients, subglottic stenosis was encountered in 4, tracheobronchial stenosis was encountered in 3, and complex stenosis was encountered in 2. The length of stenosis ranged from 0.5 cm to 2.5 cm, and the percentage of stenosis ranged from 40% to 100%. Nine patients had undergone tracheostomy and had a Montgomery T-tube in situ. Treatment was successful in 14 patients, who remained free of symptoms for at least 12 months. The number of topical applications of MMC ranged from 1 to 5, and complications included fungal infection, keloid scarring, granuloma, and mediastinal emphysema. Conclusions: MMC appears to be effective in the endoscopic treatment of tracheal stenosis.

Keywords: Tracheal stenosis; Mitomycin; Endoscopy.

Objective: The present study aimed to assess the functional status of children diagnosed with COVID-19 at the time of hospitalization and the associations with clinical features. Methods: This prospective cohort study was carried out with children diagnosed with COVID-19 admitted to a tertiary hospital. The patients' functioning was assessed using the pediatric Functional Status Scale (FSS). Results: A total of 62 children with a median age of 3 years old were included in the study, and 70% had some comorbidity prior to the diagnosis of COVID-19. The median length of stay was nine days, during which period five patients died. The FSS assessment of the sample showed that approximately 55% had some functional alteration. The group of patients with the highest FSS scores presented a lengthier hospital stay (p = 0.016), required more oxygen therapy (p < 0.001), mechanical ventilation (p = 0.001), and intensive care unit admissions (p = 0.019), and had more cardiac (p = 0.007), neurological (p = 0.003), and respiratory (p = 0.013) comorbidities. In the multivariate analysis, there was an association between the dependent variable length of stay and the total FSS score (b = 0.349, p = 0.004) and the presence of comorbidities (b = 0.357, p = 0.004). Conclusions: We observed that more than half of the children hospitalized due to COVID-19 had some level of functional change. Greater alterations in functional status were associated with the presence of previous comorbidities, a greater need for ventilatory support, and longer hospital stays.

Keywords: COVID-19, coronavirus, pediatrics, physical functional performance, functional status.

Objective: Currently, little is known about the long-term outcomes of COVID-19 in the pediatric population. The aim of this study was to investigate the long-term clinical outcomes of pediatric patients hospitalized with COVID-19. Methods: This was a prospective cohort study involving unvaccinated children and adolescents admitted to a tertiary hospital in southern Brazil with a COVID-19 diagnosis. Data were collected from electronic medical records for one year after the diagnosis. Results: A total of 66 children were included: the median age was 2.9 years; 63.6% were male; and 48.5% were under 2 years of age. Over 70% had at least one comorbidity prior to the COVID-19 diagnosis. During the one-year follow-up period, 59.1% of the children revisited the emergency department, 50% required readmission, and 15.2% died. Younger children with longer hospital stays were found to be at greater risk of readmission. Having cancer and impaired functionality were found to increase the risk of death within one year. Conclusions: Our findings indicate that most children hospitalized with COVID-19 have comorbidities. Younger age at admission and a longer hospital stay seem to be risk factors for readmission. In addition, the presence of cancer and impaired functionality are apparently associated with the poor outcome of death within the first year after the diagnosis of COVID-19.

Keywords: COVID-19; Pediatrics; Physical functional performance.

Bronchial healing remains one of the dominant issues in lung transplantation. Among other factors, the quality of airway protection during procurement may contribute to improve bronchial healing. In most centers lung preservation is performed using the pulmonary artery (PA) flush perfusion (FP). The present study was performed to investigate the influence of different routes of perfusion on the distribution of Euro-Collins solution (EUC) in lung parenchyma and upper airways in swine. The animals were divided into 4 groups, 1 without FP; Control (n=6), and the others with EUC delivery via: pulmonary artery (PA) (n=6); pulmonary and bronchial arteries simultaneously (PA+BA) (n=8), and pulmonary veins (PV). Lungs and airways were assessed by the following methods: dye-labeled microspheres for total and regional perfusion, tissue water content, and lung temperature. There was no significant difference in total lung flow between PA+BA and PA, both superior to the PV group. Flow in the proximal and distal trachea were significantly increased: PA+BA (0.970 ± 0.4 and 0.380 ± 0.2 mL/min/g, respectively); PA ( 0.023 ± 0.007 and 0.024 ± 0.07 mL/min/g, respectively); PV (0.009 ± 0.003 and 0.021 ± 0.006 mL/min/g respectively) and Control experiments (0.125 ± 0.0018 and 0.105 ±0.012 mL/min/g, respectively). The highest flow rates in the right main bronchus were achieved by PA+BA (1.04 ± 0.4 mL/min/g) as comparison to Control, PA, and PV groups (0.11 ± 0.03, 0.033 ± 0.008, and 0.019 ± 0.005 mL/min/g, respectively). Flows in the left main bronchus were significantly increased by PA+BA (0.97 ± 0.3 mL/min/g), as comparison to control, PA and PV groups (0.09 ± 0.02, 0.045 ± 0.012, and 0.027 ± 0.006 mL/min/g, respectively). In conclusion, these data showed that the distribution of EUC in airways of swine is significantly improved by PA+BA perfusion.

Keywords: Lung transplantation. Flush perfusion. Bronchial circulation. Bronchial complications.

Objectives: To determine the effect that the treatment of GERD has on the clinical management, as well as the respiratory function, of patients with asthma and to evaluate the clinical characteristics of this group of patients. Methods: Patients with asthma and concomitant GERD, documented using 24 h pH-metry, were evaluated by means of quality of life questionnaires, as well as questionnaires related to respiratory and digestive symptoms. In addition, esophageal manometry, spirometry and the determination of peak expiratory flow were also performed prior to and after the study. Forty-nine individuals who were diagnosed with GERD by means of 24 h esophageal pH-metry were selected and participated in a clinical randomized double-blind placebo-controlled study, involving the administration of 40 mg/day of pantoprazol for 12 consecutive weeks. Results: Forty-four individuals completed the study (n = 22 per group). There was significant improvement in the scores for respiratory symptoms and quality of life only in the group that received pantoprazol (p = 0.01 and p = 0.001, respectively). No respiratory function parameters changed in either group. Conclusions: In this study, the effective treatment of GERD improved patient quality of life, and the symptoms of asthma significantly decreased in the group that received the medication. There were no changes in pulmonary function parameters.

Keywords: Asthma; Gastroesophageal reflux/treatment; Diagnosis; Antacids.

Objective: To analyze the relationship between one-minute sit-to-stand test (1MSTST) parameters and a diagnosis of post COVID-19 condition in a cohort of patients who previously had COVID-19. Methods: This was a prospective cohort study of patients with post COVID-19 condition referred for body plethysmography at a tertiary university hospital. Post COVID-19 condition was defined in accordance with the current WHO criteria. Results: Fifty-three patients were analyzed. Of those, 25 (47.2%) met the clinical criteria for post COVID-19 condition. HR was lower in the patients with post COVID-19 condition than in those without it at 30 s after initiation of the 1MSTST (86.2 ± 14.3 bpm vs. 101.2 ± 14.7 bpm; p < 0.001) and at the end of the test (94.4 ± 18.2 bpm vs. 117.3 ± 15.3 bpm; p < 0.001). The ratio between HR at the end of the 1MSTST and age-predicted maximal HR (HRend/HRmax) was lower in the group of patients with post COVID-19 condition (p < 0.001). An HRend/HRmax of < 62.65% showed a sensitivity of 78.6% and a specificity of 82.0% for post COVID-19 condition. Mean SpO2 at the end of the 1MSTST was lower in the patients with post COVID-19 condition than in those without it (94.9 ± 3.6% vs. 96.8 ± 2.4%; p = 0.030). The former group of patients did fewer repetitions on the 1MSTST than did the latter (p = 0.020). Conclusions: Lower SpO2 and HR at the end of the 1MSTST, as well as lower HR at 30 s after initiation of the test, were associated with post COVID-19 condition. In the appropriate clinical setting, an HRend/HRmax of < 62.65% should raise awareness for the possibility of post COVID-19 condition.

Keywords: COVID-19; Post-acute COVID-19 syndrome; Heart rate; Respiratory function tests.

Objective: To characterise the degree of disability in pulmonary hypertension (PH) patients based on the World Health Organisation Disability Assessment Schedule 2.0 (WHODAS 2.0). Method: A prospective and observational study of patients with documented PH (N = 46). Patients completed the WHODAS 2.0 questionnaire during a scheduled routine clinical visit, and their demographic and clinical characteristics were retrieved from electronic medical records (EMR). In subsequent visits, selected clinical variables were registered to assess disease progression. Results: WHODAS 2.0 scores were indicative of mild to moderate disability for the domains of mobility (22.0 ± 23.2), life activities (23.7 ± 25.5), and participation in society (17.2 ± 15.9), as well as total WHODAS 2.0 score (15.3 ± 15.2). For the domains of cognition (9.1 ± 14.1), self-care (8.3 ± 14.4), and interpersonal relationships (11.7 ± 15.7), scores were lower. Disability scores were, generally, proportional to the PH severity. The main baseline correlates of disability were World Health Organisation (WHO) functional class, fatigue, dyspnoea, 6-minute walking distance (6MWD), and N-terminal pro b-type natriuretic peptide (NT-proBNP). Baseline WHODAS 2.0 scores showed significant associations with disease progression. However, this effect was not transversal to all domains, with only a few domains significantly associated with disease progression variables. Conclusions: This PH population shows mild disability, with higher degree of disability in the domains of mobility and life activities. This study is the first one to assess disability in PH using WHODAS 2.0. Further studies should apply this scale to larger PH populations with suitable representations of more severe PH forms.

Keywords: Pulmonary hypertension; International Classification of Functioning, Disability and Health; Disability evaluation; Quality of Life.

The DNA vaccines currently under pre-clinical and clinical development may prove to be important tools in combating infectious diseases, such as tuberculosis, for which no safe and effective form of prevention has yet been developed. In recent years, several studies have aimed to develop a DNA vaccine encoding mycobacterial proteins such as antigen 85 (Ag85) and the 65-kDa mycobacterial heat shock protein (hsp65). The latter is protective against virulent infection with Mycobacterium tuberculosis (including multidrugresistant strains). The hsp65 DNA vaccine, currently under clinical evaluation in Brazil for cancer therapy, is able to induce the secretion of Th1 cytokines, such as gamma-interferon, associated with disease control. Furthermore, this vaccine stimulates cytotoxic CD8 and CD4 T-cell clones that can be characterized as memory cells, which are responsible for effective and longlasting immunity against tuberculosis. When used as a therapeutic agent in inoculated mice, the hsp65 DNA vaccine promotes changes in the immunity profile, triggering the secretion of Th1 cytokines and establishing a favorable environment for the elimination of bacilli. The results also demonstrate that the route of administration, as well as the formulation in which the vaccine is administered, fundamentally influence the pattern and duration of the immune response induced. Taking all currently available data into account, we can conclude that a DNA vaccine against tuberculosis could contribute significantly to the control of the disease.

Keywords: Tuberculosis/epidemiology. Vaccines, DNA/therapeutic use. Heat shock proteins. Auto-immunity.

Objective: Obstructive sleep apnea (OSA) is associated with an increased risk of mortality and cardiometabolic diseases. The STOP-Bang questionnaire is a tool to screen populations at risk of OSA and prioritize complementary studies. Our objective was to evaluate the clinical utility of this questionnaire in identifying patients at an increased risk of mortality after discharge in a cohort of hospitalized patients. Methods: This was a prospective cohort study involving consecutive patients admitted to an internal medicine unit between May and June of 2017 who were reevaluated three years after discharge. At baseline, we collected data on comorbidities (hypertension, obesity, diabetes, and fasting lipid profile) and calculated STOP-Bang scores, defining the risk of OSA (0-2 score, no risk; = 3 score, risk of OSA; and = 5 score, risk of moderate-to-severe OSA), which determined the study groups. We also recorded data regarding all-cause and cardiovascular mortality at the end of the follow-up period. Results: The sample comprised 435 patients. Of those, 352 (80.9%) and 182 (41.8%) had STOP-Bang scores = 3 and = 5, respectively. When compared with the group with STOP-Bang scores of 0-2, the two groups showed higher prevalences of obesity, hypertension, diabetes, and dyslipidemia. Multivariate analysis showed an independent association between cardiovascular mortality and STOP-Bang score = 5 (adjusted hazard ratio = 3.12 [95% CI, 1.39-7.03]; p = 0.01). Additionally, previous coronary heart disease was also associated with cardiovascular mortality. Conclusions: In this cohort of hospitalized patients, STOP-Bang scores = 5 were able to identify patients at an increased risk of cardiovascular mortality three years after discharge.

Keywords: Sleep Apnea, Obstructive; Risk assessment; Surveys and questionnaires; Cardiovascular diseases/mortality.

Objective: To establish the incidence of acute lung injury and acute respiratory distress syndrome, as well as related risk factors and mortality in an intensive care unit. To compare patients developing lung injury with at-risk patients not presenting acute lung injury or acute respiratory distress syndrome. Methods: The study was conducted in the intensive care unit of the Ribeirão Preto Hospital das Clínicas Emergency Room. All patients admitted between May 2001 and April 2002 were monitored prospectively. Clinical data, Acute Physiologic and Chronic Health Evaluation II score, complications, length of stay in the intensive care unit and lung injury data were recorded. Results: Of the 524 patients admitted, 175 (33.4%) presented risk factors for acute lung injury and acute respiratory distress syndrome, 33 (6.3%) developed acute respiratory distress syndrome, and 12 (2.3%) developed acute lung injury. The main risk factors were pneumonia (37.7%), shock (32.0%), multiple trauma (24.6%) and sepsis (21.1%). Patients developing acute lung injury had higher Acute Physiologic and Chronic Health Evaluation II scores (p < 0.05), more frequently presented sepsis (p = 0.001), developed more complications (p = 0.001) and presented greater mortality (p = 0.001). The main cause of death was multiple organ failure (38.5%). Conclusion: The incidence of acute lung injury and acute respiratory distress syndrome was 2.3% and 6.3%, respectively.

Keywords: Respiratory distress syndrome, adult/epidemiology; Respiratory distress syndrome, adult/mortality;

Objective: Because SARS-CoV-2 infection can severely affect the lungs and persistent functional changes can occur after severe disease, we aimed to determine lung function parameters of COVID-19 patients at 45 days after hospital discharge and compare changes according to the severity of the disease. Methods: This was a prospective descriptive analytical multicenter study. The participants were allocated into three groups: ward admission (WA) group; ICU admission not on mechanical ventilation (ICU/MV-) group; and ICU admission on MV (ICU/MV+) group. Lung volumes, DLco, MIP, MEP, and six-minute walk distance (6MWD) were measured 45 days after discharge. Results: The sample comprised 242 patients (mean age = 59.4 ± 14.8 years; 52.1% of males), and 232 (96%) had altered lung function. In the total cohort, restrictive disorder was observed in 96%, as well as reductions in DLco (in 21.2% of the patients), FEV1/FVC (in 39.7%), and PEmax (in 95.8%), with no differences between the groups. Comparing the groups, the ICU/MV+ group had reduced DLco in 50% of the patients (p < 0.001) and a lower mean 6MWD % of the predicted value (p = 0.013). Oxygen desaturation in the six-minute walk test was observed in 32.3% of the cohort and was less frequent in the IE group. Conclusions: This is the first South American study involving severe COVID-19 survivors whose lung function was assessed 45 days after hospital discharge. Changes were frequent, especially in those on MV, which highlights the importance of lung function evaluation after severe COVID-19.

Keywords: COVID-19; Respiratory function tests; Pulmonary diffusing capacity; Virus disease; SARS-CoV-2.

Requesting passive cooperation from the patient and supplying new parameters for the analysis of the ventilatory mechanics, the forced oscillations technique (FOT) has complementary characteristics to the classical methods of lung evaluation. In this work, a review of the principles of this technique is initially presented together with a discussion about its advantages and present limitations. The performance of the technique is compared to classical methods in the detection of breathing disorders. The main clinical applications reported previously in the literature, including the evaluation of the ventilatory mechanics in children, studies in neonates, monitoring of patients under mechanical ventilation, occupational medicine, and evaluation of respiratory sleep disturbances are reviewed and discussed. Based on this review and on the results obtained in studies made in their laboratory, the authors concluded that FOT could render a more detailed examination and facilitate the accomplishment of lung function tests under conditions in which traditional techniques are not appropriate.

Keywords: respiratory mechanics, oscillometry, respiratory function tests