Objective: To use clinical and spirometry findings in order to distinguish between the restrictive and nonspecific patterns of pulmonary function test results in patients with low FVC and a normal or elevated FEV1/FVC ratio. Methods: We analyzed the pulmonary function test results of 211 adult patients submitted to spirometry and lung volume measurements. We used the clinical diagnosis at the time spirometry was ordered, together with various functional data, in order to distinguish between patients presenting with a "true" restrictive pattern (reduced TLC) and those presenting with a nonspecific pattern (normal TLC). Results: In the study sample, TLC was reduced in 144 cases and was within the normal range in 67. The most common causes of a nonspecific pattern were obstructive disorders, congestive heart failure, obesity, bronchiolitis, interstitial diseases, and neuromuscular disorders. In patients given a working diagnosis of pulmonary fibrosis, pleural disease, or chest wall disease, the positive predictive value (PPV) for restriction was ≥ 90%. In males, an FVC ≤ 60% of predicted had a PPV for restriction of 98.8%. In females, the restrictive pattern was found in 84.4% of those with an FVC ≤ 50% of predicted. A difference of ≥ 0% between the FEV1% and the FVC% had a PPV for restriction of 89.5%. After performing logistic regression, we developed a point scale for predicting the restrictive pattern. Conclusions: In many patients with reduced FEV1, reduced FVC, and a normal FEV1/FVC ratio, the restrictive pattern can be identified with confidence through the use of an algorithm that takes the clinical diagnosis and certain spirometry measurements into account.

Keywords: Spirometry; Airway resistance; Respiratory function tests; Vital capacity.

Objective: To evaluate the spirometry values predicted by the 2012 Global Lung Function Initia-tive (GLI) equations, which are recommended for international use, in comparison with those obtained for a sample of White adults used for the establishment of reference equations for spirometry in Brazil. Methods: The sample comprised 270 and 373 healthy males and females, respectively. The mean differences between the values found in this sample and the predicted values calculated from the GLI equations for FVC, FEV1, and VEF1/FVC, as well as their lower lim-its, were compared by paired t-test. The predicted values by each pair of equations were com-pared in various combinations of age and height. Results: For the males in our study sample, the values obtained for all of the variables studied were significantly higher than those predicted by the GLI equations (p < 0.01 for all). These differences become more evident in subjects who were shorter in stature and older. For the females in our study sample, only the lower limit of the FEV1/FVC ratio was significantly higher than that predicted by the GLI equation. Conclusions: The predicted values suggested by the GLI equations for White adults were significantly lower than those used as reference values for males in Brazil. For both genders, the lower limit of the FEV1/FVC ratio is significantly lower than that predicted by the GLI equations.

Keywords: Respiratory function tests/statistics and numerical data; Respiratory function tests/diagnosis; Reference values.

Objective: To determine the efficacy of using forced expiratory volume in six seconds (FEV6) as a surrogate for forced vital capacity (FVC) in the diagnostic screening for chronic obstructive pulmonary disease (COPD) by comparing FEV1/FVC ratios with FEV1/FEV6 ratios. Methods: In November of 2003, on World COPD Day, we conducted a campaign of diagnostic screening for COPD. The participants completed the clinical questionnaire of the Global Initiative for Obstructive Lung Disease, and those who responded affirmatively to at least three questions underwent spirometry. Results: A total of 134 individuals responded to three questions affirmatively and underwent spirometry. Of those, 59 were excluded: 45 for being non-smokers and 14 due to the fact that their tests did not meet the American Thoracic Society criteria for satisfactory spirometry. The number of tests in which the FEV1/FEV6 ratio was below 70% was similar to that found for the FEV1/FVC ratio. The sensitivity of FEV1/FEV6 in diagnosing airway obstruction (defined as FEV1/FVC below 70%) was 92%, and its specificity was 99%. The positive predictive value was 100%, and the negative predictive value was 98%. The Kendall correlation test revealed r = 0.99 (p < 0.0001). The t-test for paired samples revealed a negative correlation: t = −5.93 (p < 0.0001). Conclusion: The FEV1/FEV6 proved efficient for use in the diagnostic screening for COPD. There is a strong correlation between FEV1/FVC and FEV1/FEV6.

Keywords: Pulmonary disease, Chronic obstructive; Diagnosis; Spirometry; Forced expiratory volume; Vital capacity.

Objective: To evaluate the ability of COPD patients to perform activities of daily living (ADL); to identify barriers that prevent these individuals from performing ADL; and to correlate those barriers with dyspnea severity, six-minute walk test (6MWT), and an ADL limitation score. Methods: In COPD patients and healthy, age-matched controls, the number of steps, the distance walked, and walking time were recorded with a triaxial accelerometer, for seven consecutive days. A questionnaire regarding perceived barriers and the London Chest Activity of Daily Living (LCADL) scale were used in order to identify the factors that prevent the performance of ADL. The severity of dyspnea was assessed with two scales, whereas submaximal exercise capacity was determined on the basis of the 6MWT. Results: We evaluated 40 COPD patients and 40 controls. In comparison with the control values, the mean walk time was significantly shorter for COPD patients (68.5  25.8 min/day vs. 105.2  49.4 min/day; p < 0.001), as was the distance walked (3.9  1.9 km/day vs. 6.4  3.2 km/day; p < 0.001). The COPD patients also walked fewer steps/day. The most common self-reported barriers to performing ADL were lack of infrastructure, social influences, and lack of willpower. The 6MWT distance correlated with the results obtained with the accelerometer but not with the LCADL scale results. Conclusions: Patients with COPD are less active than are healthy adults of a comparable age. Physical inactivity and the barriers to performing ADL have immediate implications for clinical practice, calling for early intervention measures.

Keywords: Pulmonary disease, chronic obstructive; Activities of daily living; Exercise tolerance.

The authors report the case of a 7-year-old girl, with a history of recurrent respiratory infections since five months of age. Immunological evaluation at four years of age revealed a normal level of total serum immunoglobulins, but a deficient humoral response to Streptococcus pneumoniae. Although having all normal IgG subclasses, the patient had inadequate antibody levels to all serotypes tested (1, 3, 5, 6, 9, and 14). Concurrent radiological evaluation showed diffuse atelectasis and bronchiectasis. Patient was started on IVIG, and subsequent chest CT scan revealed resolution of the above-mentioned lesions. To prevent irreversible damage to lung parenchyma, due to recurrent lower respiratory infections, it is important to identify immunocompromised individuals and treat them accordingly.

Keywords: Immunologic deficiency syndromes. Streptococcus pneumoniae.

Objective: One of the common limitations after COVID-19 pneumonia is the decrease in exercise capacity. The identification of the factors affecting exercise capacity and the assessment of patients at risk are important for determining treatment strategy. This study was conducted to determine the predictors of decreased exercise capacity in long post-COVID-19 patients. Methods: We investigated the association of exercise capacity as measured by the incremental shuttle walk test (ISWT) with age, sex, spirometric variables, respiratory and peripheral muscle strength, quality of life, fatigue, hospital anxiety depression scale, chest X-ray involvement, and hospitalization. The patients were divided into three groups: outpatients, inpatients, and ICU patients. Regression analysis was used to determine which parameters were significant predictors of exercise capacity. Results: Of the 181 patients included in the study, 56 (31%) were female. The mean ISWT in percentage of predicted values (ISWT%pred) was 43.20% in the whole sample, whereas that was 52.89%, 43.71%, and 32.21% in the outpatient, inpatient, and ICU patient groups, respectively. Linear regression analysis showed that predictors of decreased ISWT%pred were sex (ß = 8.089; p = 0.002), mMRC scale score (ß = -7.004; p = 0.001), FVC%pred (ß = 0.151; p = 0.003), and handgrip strength (ß = 0.261; p = 0.030). Conclusions: In long post-COVID-19 patients, sex, perception of dyspnea, restrictive pattern in respiratory function, and decrease in peripheral muscle strength are predictors of reduced exercise capacity that persists three months after COVID-19. In this context, we suggest that pulmonary rehabilitation might be an important therapy for patients after COVID-19.

Keywords: COVID-19; Exercise; Muscle strength; Rehabilitation; Walk test.

Objective: To compare equations for predicting peak quadriceps femoris (QF) muscle force; to determine the agreement among the equations in identifying QF muscle weakness in COPD patients; and to assess the differences in characteristics among the groups of patients classified as having or not having QF muscle weakness by each equation. Methods: Fifty-six COPD patients underwent assessment of peak QF muscle force by dynamometry (maximal voluntary isometric contraction of knee extension). Predicted values were calculated with three equations: an age-height-weight-gender equation (Eq-AHWG); an age-weight-gender equation (Eq-AWG); and an age-fat-free mass-gender equation (Eq-AFFMG). Results: Comparison of the percentage of predicted values obtained with the three equations showed that the Eq-AHWG gave higher values than did the Eq-AWG and Eq-AFFMG, with no difference between the last two. The Eq-AHWG showed moderate agreement with the Eq-AWG and Eq-AFFMG, whereas the last two also showed moderate, albeit lower, agreement with each other. In the sample as a whole, QF muscle weakness (< 80% of predicted) was identified by the Eq-AHWG, Eq-AWG, and Eq-AFFMG in 59%, 68%, and 70% of the patients, respectively (p > 0.05). Age, fat-free mass, and body mass index are characteristics that differentiate between patients with and without QF muscle weakness. Conclusions: The three equations were statistically equivalent in classifying COPD patients as having or not having QF muscle weakness. However, the Eq-AHWG gave higher peak force values than did the Eq-AWG and the Eq-AFFMG, as well as showing greater agreement with the other equations.

Keywords: Pulmonary disease, chronic obstructive; Muscle strength; Quadriceps muscle; Reference values.

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 evaluate the association between degree of asthma control and health-related quality of life in patients with moderate or severe asthma. Methods: This was a descriptive observational study involving 59 outpatients with moderate or severe asthma under treatment at the Asthma Outpatient Clinic of the Federal University of Ceará Walter Cantídio University Hospital, in the city of Fortaleza, Brazil. The patients were evaluated regarding sociodemographic and clinical characteristics, as well as spirometric parameters. The asthma control status was assessed using the asthma control test (ACT), and quality of life was assessed using the Saint George's Respiratory Questionnaire (SGRQ). Results: The mean age of the patients was 55.0 ± 12.4 years, and 76.3% were female. The ACT score showed statistically significant negative correlations with all SGRQ scores: total (r = −0.72); symptoms (r = −0.78); activity (r = −0.67); and impact (r = −0.68). Multiple regression analysis showed that the most robust predictive variables for SGRQ total score were ACT score (coefficient = −3.18; 95% CI: −4.14 to −2.23) and duration of disease (coefficient = −0.29; 95% CI: −0.54 to −0.03). The ACT score also explained the linear variation of the SGRQ domains: symptoms (coefficient = −3.41; 95% CI: −4.45 to −2.37); activity (coefficient = −3.07; 95% CI: −4.57 to −1.57); and impact (coefficient = −2.68; 95% CI: −3.71 to −1.65). Conclusions: The degree of asthma control appears to have a significant impact on health-related quality of life.

Keywords: Asthma/prevention and control; Quality of life; Questionnaires.

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.

Background: Normal diagnosis of clubbing is clinical; however use of objective criteria may improve the accuracy of findings Objective: To present a simple method of obtaining finger images for the purpose of studying clubbing. Method: Shadow images of the index fingers obtained by projection through a transparent glass plate virtually without distortion and displayed on a common sheet of paper yielded the profile (PA) and hyponychial (HA) angles; as well as the ratio between distal phalangean and interphalangean depths (DPD/IPD). Upon physical examination of 306 adult bearers of pulmonary disease, 116 disclosed presence of clubbing (YES); 126 absence (NO); and 64 were doubtful cases (DBT). Also studied were 452 normal adult individuals. Among these 71.0% of the bearers and 33.4% of the controls were smokers. Results: Values found in normal individuals and in patients bearers of clubbing (YES) were, respectively, 172.8±5.9º vs. 183.4±5.9º for PA, 181.5±5.0º vs. 201.4±6.5º for HA, and 0.904±0.029 vs. 1.014±0.062 for DPD/IPD (significant differences, p<0.001). In the doubtful) cases (DBT) the three values were also higher than in normal controls (p<0.001). Furthermore, it was shown that among controls PA, HA and the DPD/IPD ratios were significantly larger in male smokers (p<0.005) while only the DPD/IPD ratio was larger in female smokers (p<0.05). Conclusions: This is a simple method of obtaining clear index finger images. The hyponychial angle determined on the images was the most useful measurement to discriminate digits clinically with and without clubbing (sensitivity of 76.7%, specificity of 83.2%, predictive positive value of 95.5% and predictive negative value of 96.9%).

Keywords: Clubbing, profile angle, hyponychial angle, relation DPD/IPD.

Objective: To describe the performance of a pulmonologist-led lung cancer screening pro-gram using low dose CT (LDCT) in a cohort of outpatients with stable respiratory diseases in the Brazilian public health care system. Methods: This was a retrospective analysis of the first two rounds of lung cancer screening of patients enrolled in the program. Inclusion criteria were being between 55 and 80 years of age, being a current or former smoker (smoking cessation = 15 years), and having a smoking history = 30 pack-years. LDCT results were interpreted in accordance with the Lung CT Screening Reporting and Data System, and those with a score of 3 or 4 were considered posi-tive screening. Incidental pleuropulmonary findings were sought in all reports. Results: LDCTs were requested for 791 patients during the study period, and 712 patients (90%) met the screening criteria. The mean patient age was 63 years, and most participants were current smokers (56%) with emphysema (78.5%) and other pleuropulmonary findings on CT (64%). Screening was positive in 14.0% and 5.6% of the cases in the first and second screening rounds, respectively. Lung cancer was detected in 1.5% of the patients in both first and second rounds (positive predictive value: 11.0% and 26.6%, respectively). The rate of early-stage (TNM I or II) screen-detected non-small cell carcinoma was 64.3%. Of the patients with positive screening, 19% were lost to follow-up before investigation was complete. Conclusions: The results of this screening program suggest its adequate performance in a cohort of patients with significant respiratory morbidity. The loss to follow-up rate highlights the need for constant monitoring and interventions to ensure adherence.

Keywords: Lung neoplasms; Diagnostic screening programs; Early detection of cancer; Brazil; Tuberculosis.

Objective: Smoking prevalence is frequently estimated on the basis of self-reported smoking status. That can lead to an underestimation of smoking rates. The aim of this study was to evaluate the difference between self-reported smoking status and that determined through the use of objective measures of smoking at a pulmonary outpatient clinic. Methods: This was a cross-sectional study involving 144 individuals: 51 asthma patients, 53 COPD patients, 20 current smokers, and 20 never-smokers. Smoking status was determined on the basis of self-reports obtained in interviews, as well as through tests of exhaled carbon monoxide (eCO) and urinary cotinine. Results: All of the asthma patients and COPD patients declared they were not current smokers. In the COPD and asthma patients, the median urinary cotinine concentration was 167 ng/mL (range, 2-5,348 ng/mL) and 47 ng/mL (range, 5-2,735 ng/mL), respectively (p < 0.0001), whereas the median eCO level was 8 ppm (range, 0-31 ppm) and 5 ppm (range, 2-45 ppm), respectively (p < 0.05). In 40 (38%) of the patients with asthma or COPD (n = 104), there was disagreement between the self-reported smoking status and that determined on the basis of the urinary cotinine concentration, a concentration > 200 ng/mL being considered indicative of current smoking. In 48 (46%) of those 104 patients, the self-reported non-smoking status was refuted by an eCO level > 6 ppm, which is also considered indicative of current smoking. In 30 (29%) of the patients with asthma or COPD, the urinary cotinine concentration and the eCO level both belied the patient claims of not being current smokers. Conclusions: Our findings suggest that high proportions of smoking pulmonary patients with lung disease falsely declare themselves to be nonsmokers. The accurate classification of smoking status is pivotal to the treatment of lung diseases. Objective measures of smoking could be helpful in improving clinical management and counseling.

Keywords: Asthma; Pulmonary disease, chronic obstructive; Cotinine; Carbon monoxide; Smoking.

Objective: To evaluate the effects of non-invasive positive pressure ventilation (NIPPV) on acute respiratory failure and to identify the factors associated with its failure or success. Patients and methods: This open and prospective study analyzed 60 episodes of NIPPV use in 53 patients with respiratory failure. Results: In 37 occasions (62%), the patients were successfully ventilated with NIPPV (Success Group, SG) whereas in 23 episodes (38%) intubation was necessary (Failure Group, FG). FG patients showed a higher Apache II score (30.4 ± 9 versus 22.2 ± 8, p = 0.001). The use of NIPPV reduced respiratory rate after 2 hs. This reduction was less evident in FG (from 33 ± 9 to 30 ± 8 bpm, p = 0.094) than in SG (from 39 ± 11 to 28 ± 9 bpm, p < 0.001). PaO2 increased from 62 ± 22 to 101 ± 65 mmHg, (p < 0.001) with no differences between groups. Among patients with hypercapnia, PaCO2 level decreased in SG (from 76 ± 20 to 68 ± 21mmHg, p = 0.032) but not in FG (from 89 ± 23 to 93 ± 40mmHg, p = 0.54). Arterial pH increased in SG (from 7.25 ± 0.10 to 7.34 ± 0.11, p = 0.007) and not in FG (from 7.24 ± 0.07 to 7.21 ± 0.12, p = 0.48). NIPPV was used for longer in SG (3.4 ± 2.5 versus 2.3 ± 2 days, p = 0.003). Higher IPAP levels were used in SG (13.2 ± 3 versus 11 ± 4cmH2O, p = 0.02). The 10 patients (17%) who died, all belonged to FG. Skin lesions at the site of mask contact was the most common complication of NIPPV (5, 8%). NIPPV was efficient in treating acute respiratory failure in 2/3 of patients. The factors associated with failure were: greater severity of the illness, smaller reduction in the respiratory rate, no improvement of respiratory acidosis in 2 h and use of lower IPAP levels. The high mortality rate observed in FG (10, 43%) justifies efforts to optimize NIPPV implementation and to recognize its failure, as early as possible, in order to avoid delays in endotracheal intubation.

Keywords: Non-invasive positive pressure ventilation. Respiratory failure. Apache II. Hypercapnia.

Objective: To compare clinical and pathological staging in patients with non-small cell lung cancer submitted to surgical treatment, as well as to identify the causes of discordance. Methods: Data related to patients treated at the Department of Thoracic Surgery of the Pontifical Catholic University of Rio Grande do Sul São Lucas Hospital were analyzed retrospectively. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were calculated for clinical stages IA, IB, and IIB. The kappa index was used to determine the concordance between clinical and pathological staging. Results: Of the 92 patients studied, 33.7% were classified as clinical stage IA, 50% as IB, and 16.3% as IIB. The concordance between clinical and pathological staging was 67.5% for stage IA, 54.3% for IB, and 66.6% for IIB. The accuracy of the clinical staging was greater for stage IA, and a kappa of 0.74, in this case, confirmed a substantial association with pathological staging. The difficulty in evaluating nodal metastatic disease is responsible for the low concordance in patients with clinical stage IB. Conclusions: The concordance between clinical and pathological staging is low, and patients are frequently understaged (in the present study, only one case was overstaged). Strategies are necessary to improve clinical staging and, consequently, the treatment and prognosis of patients with non-small cell lung cancer.

Keywords: Neoplasm staging; Lung neoplasms/diagnosis; Lung neoplasms/surgery; Prognosis.