Objective: To evaluate the use of the forced expiratory volume in one second/forced expiratory volume in six seconds (FEV1/FEV6) ratio as an alternative to the FEV1/forced vital capacity (FVC) ratio in the detection of mild airway obstruction. Methods: Reference equations for the Brazilian population in 2006 were used in order to determine the lower limits of normality for the FEV1/FEV6 and FEV1/FVC ratios. The spirometry findings of 155 patients from 20 to 84 years of age were analyzed. All of the patients presented the following: a < 15% difference between predicted and observed FEV1/FVC ratio; an FEV1 ≥ 60% of predicted; and an exhalation time of at least 6 s. The Brazilian Thoracic Society criteria for acceptability and reproducibility in spirometry were met. Results: Mean values (± SD) for FEV1/FEV6 and FEV1/FVC were 73 ± 4% and 75 ± 3%, respectively. Using the FEV1/FVC ratio, we identified airflow obstruction in 61 patients, compared with only 46 patients when we used the FEV1/FEV6 ratio, showing a sensitivity of 75% (p < 0.001). Conclusions: The FEV1/FEV6 ratio has poor sensitivity and should not be used to replace the FEV1/FVC ratio in the diagnosis of mild airway obstruction.

Keywords: Forced expiratory volume; Vital capacity; Airway obstruction; Spirometry; Respiratory function tests.

Background: This study evaluated the perception of airway obstruction in moderate to severely asthmatic outpatients and the efficiency of chest auscultation in identifying airflow limitation. Methods: 33 subjects were evaluated at seven weekly visits by using symptoms scores determined by visual analogue scales (VAS, 0-100 mm), a clinical index of bronchial hyperreactivity (1-10), the clinical classification of asthma severity (GINA, 1-4) and a thoracic auscultation score (TAS, 0-5), spirometry and peak expiratory flow (PEF), which were correlated by the coefficient of Spearman. Patients were classified as perceivers (-1 £ r < 0) or nonperceivers (0 £ r £ 1) by correlations between VAS for dyspnoea and FEV1. A correlation between auscultation and bronchial obstruction was considered accurate when a r £ -0.5 (TAS vs. FEV1) was found. Results: Seventeen asthmatic patients (51.5%) did not accurately perceive the degree of their airways obstruction (nonperceivers). No clinical characteristics distinguished the groups. Only 39.4% of the individual correlations between TAS and FEV1 indicated accurate discrimination by auscultation. Severe asthma was not associated with inaccurate auscultation nor with malperception in this study. Conclusions: A significant proportion of this sample of asthmatic patients did not accurately perceive their own airway obstruction. Moreover, chest examination was shown to be an unsuitable discriminator of airflow limitation in moderate to severe stable asthmatics in an outpatient clinic.

Keywords: Asthma. Airway obstruction. Auscultation. Lung obstructive diseases.

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 determine the relative frequency of hypomagnesemia among patients with chronic airflow limitation treated as outpatients at a referral center in the northern part of the state of Paraná between 2000 and 2001, as well as to determine whether hypomagnesemia correlates with hypoxia, with other electrolyte disturbances and with the severity of airflow limitation. Methods: This was a descriptive study of the relative frequency of hypomagnesemia in 72 patients with chronic airflow limitation. All of the patients were submitted to blood tests to determine serum levels of magnesium and other electrolytes, as well as to staging of the underlying disease. Results: The prevalence of hypomagnesemia was 27.8%. The mean age was 65 ± 9.9 years, and there was a predominance of males. The mean forced expiratory volume in one second was 1.31 ± 0.52 L. Most of the patients (68.1%) were found to be in the advanced stages of the disease. Hypomagnesemia was not found to correlate with other electrolyte disturbances, hypoxemia or disease stage. Conclusion: The high frequency of patients in the advanced stages is likely attributable to the fact that the outpatient facility is a referral center for the region. Further studies should be conducted in order to determine the probable causes of this high prevalence of hypomagnesemia.

Keywords: Magnesium/blood; Pulmonary ventilation; Pulmonary disease, chronic obstructive; Respiratory insufficiency

Objective: To compare the most recent (2006) predicted values of forced vital capacity and forced expiratory volume in one second for spirometry in Brazilians with those obtained using other reference equations and to validate the findings through comparisons with a new sample of normal Brazilians. Methods: Forced spirometry was performed, in accordance with the Brazilian Thoracic Society guidelines, in 643 nonsmoking adult Caucasians. The predicted values obtained by Brazilian researchers in 1992 and those obtained by four groups of foreign researchers were compared with the new Brazilian predicted values obtained in 2006. In the second phase, the mean values obtained in 65 adult females and 79 adult males were compared with the predicted values obtained using the various reference equations. Results: A t-test for paired samples revealed significant differences between the predicted values obtained using the six equations and those obtained using the 2006 Brazilian equation. In the second phase, the mean predicted values obtained by Crapo et al., as well as those obtained by Hankinson et al. for Mexican-Americans, were similar to those found in the new sample. However, when the predicted values obtained in the new sample were compared with those obtained by those authors, discrepancies were found, with high and low predicted values. The mean values obtained using the 2006 Brazilian equation presented the smallest differences in comparison with the mean values obtained in the new sample. Conclusions: These results underscore the importance of using prediction equations for spirometry that are appropriate for our population.

Keywords: Spirometry; Reference values; Respiratory function tests.

Objective: To compare 90-day morbidity in patients undergoing lung lobectomy performed by either robotic-assisted thoracic surgery (RATS) or video-assisted thoracic surgery (VATS). Intraoperative complications, drainage time, length of hospital stay, postoperative pain, postoperative quality of life, and readmissions within 90 days were also compared. Methods: This was a two-arm randomized clinical trial including patients with lung lesions (primary lung cancer or lung metastasis) who were candidates for lung lobectomy. Patients with comorbidities that precluded surgical treatment were excluded. All patients followed the same postoperative protocol. Results: The overall sample comprised 76 patients (39 in the VATS group and 37 in the RATS group). The two groups were similar regarding gender, age, BMI, FEV1 in % of predicted, and comorbidities. Postoperative complications within 90 days tended to be more common in the VATS group than in the RATS group, but the difference was not significant (p = 0.12). However, when only major complications were analyzed, this tendency disappeared (p = 0.58). Regarding postoperative outcomes, the VATS group had a significantly higher number of readmissions within 90 days than did the RATS group (p = 0.029). No significant differences were found regarding intraoperative complications, drainage time, length of hospital stay, postoperative pain, and postoperative quality of life. Conclusions: RATS and VATS lobectomy had similar 90-day outcomes. However, RATS lobectomy was associated with a significant reduction in the 90-day hospital readmission rate. Larger studies are necessary to confirm such a finding. (ClinicalTrials.gov identifier: NCT02292914 [http://www.clinicaltrials.gov/])

Keywords: Robotic surgical procedures; Thoracic surgery, video-assisted; Lung neoplasms.

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.

1. LabSono, Hospital Mãe de Deus Center, Porto Alegre (RS) Brasil. 2. Laboratório do Sono, Laboratório de Investigação Médica 63, Divisão de Pneumologia, Instituto do Coração – InCor – Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo – HCFMUSP – São Paulo (SP) Brasil.

Objective: To correlate the postbronchodilator (post-BD) inspiratory capacity (IC), % of predicted, with other markers of severity and prognostic factors in chronic obstructive pulmonary disease (COPD). Methods: Eighty stable patients with COPD performed forced vital capacity and slow vital capacity maneuvers, as well as the 6-min walk test, prior to and after receiving albuterol spray (400 μg). Patients were divided into four groups, based on post-BD forced expiratory volume in one second. Several variables were tested to establish correlations with the post-BD distance walked, using univariate and multivariate analysis. Post-BD IC was found to correlated with Global Initiative for Chronic Obstructive Lung Disease (GOLD) staging and with the Body mass index, airway Obstruction, Dyspnea, and Exercise capacity (BODE) index. Results: Multivariate regression analysis revealed that the distance walked, % predicted, correlated significantly with the IC post-BD, % predicted (p = 0.001), long-term oxygen use (p = 0.014), and number of medications used in the treatment (p = 0.044). IC ≤ 70% was observed in 56% patients in GOLD stages 3 or 4 vs. 20% in GOLD 1 or 2 (p < 0.001). IC ≤ 70% was observed in (60%) patients with BODE score 3 or 4 vs. (33%) BODE score 1 or 2 (p = 0.02). Conclusion: Post-BD IC% predicted is the best functional predictor of distance walked and is significantly associated with GOLD staging and BODE index. Therefore, We propose that the inspiratory capacity should be added to the routine evaluation of the COPD patients.

Keywords: Pulmonary disease, chronic obstructive; Walking; Respiratory function tests; Inspiratory 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.

The objective of this systematic review was to characterize chest CT findings in patients with dysphagia and pulmonary aspiration, identifying the characteristics and the methods used. The studies were selected from among those indexed in the Brazilian Virtual Library of Health, LILACS, Indice Bibliográfico Español de Ciencias de la Salud, Medline, Cochrane Library, SciELO, and PubMed databases. The search was carried out between June and July of 2016. Five articles were included and reviewed, all of them carried out in the last five years, published in English, and coming from different countries. The sample size in the selected studies ranged from 43 to 56 patients, with a predominance of adult and elderly subjects. The tomographic findings in patients with dysphagia-related aspiration were varied, including bronchiectasis, bronchial wall thickening, pulmonary nodules, consolidations, pleural effusion, ground-glass attenuation, atelectasis, septal thickening, fibrosis, and air trapping. Evidence suggests that chest CT findings in patients with aspiration are diverse. In this review, it was not possible to establish a consensus that could characterize a pattern of pulmonary aspiration in patients with dysphagia, further studies of the topic being needed.

Keywords: Respiratory aspiration; Tomography, X-ray computed; Lung.

Objective: To determine the prevalence of asthma symptoms and of airflow obstruction in amateur swimmers between 8 and 17 years of age, as well as to assess the awareness of asthma and asthma management among these swimmers, their parents, and their coaches. Methods: Our sample comprised 1,116 amateur swimmers who completed a modified version of the International Study of Asthma and Allergies in Childhood written questionnaire, to which questions regarding the reasons to initiate swimming and regarding asthma management had been added. In addition, the participants underwent spirometry prior to a swimming competition. Results:   The prevalence of asthma symptoms in the last 12 months was 11.5%, and 327 (29.4%) of the participants reported "wheezing or whistling" in the past. Of the 223 swimmers who reported "asthma ever" or "bronchitis ever", only 102 (45.7%) reported having ever been treated: the most common "treatment" was swimming (in 37.3%), and only 12.7% used inhaled corticosteroids. Of the 254 participants (22.7%) with airflow obstruction, only 52  (20.5%) reported having asthma symptoms. Conclusions: Asthma symptoms are present in amateur swimmers, and a considerable number of such swimmers have airflow obstruction without symptoms. It is therefore likely that the prevalence of asthma is underestimated in this population. It is worrisome that, in our study sample, the swimmers previously diagnosed with asthma were not using the recommended treatments for asthma. The clinical implications of these findings underscore the importance of implementing educational measures for amateur swimmers, as well as for their parents and coaches, to help them recognize asthma symptoms and the consequent risks in the sports environment, in order to allow prompt diagnosis and early clinical intervention.

Keywords: Asthma/diagnosis; Asthma/prevention & control; Sports.