Objective: To determine the proportion of asthma patients with a poor perception of dyspnea, correlating the level of that perception with the severity of acute bronchoconstriction, bronchial hyperresponsiveness, use of maintenance medication, and asthma control. Methods: Uncontrolled clinical trial involving asthma patients treated at the Pulmonology Outpatient Clinic of the São Lucas Hospital, in Porto Alegre, Brazil. Methacholine challenge testing was performed using a five-breath dosimeter protocol. The perception of dyspnea after each breath was determined using the Borg scale. Data concerning asthma control, medication in use, and use of rescue short-acting bronchodilators were recorded. Results: Of the 65 patients included in the study, 53 completed the evaluation. Of those, 32 (60.5%) showed adequate perception of dyspnea after the methacholine challenge test, whereas 21 (39.5%) did not perceive any changes in the degree of dyspnea even after a 20% fall in FEV1. There were no significant differences between the two groups regarding baseline FEV1, percentage fall in FEV1, and the dose of methacholine causing a 20% fall in FEV1. The perception of dyspnea was not significantly associated with age (p = 0.247); gender (p = 0.329); use of maintenance medication (p = 0.152); asthma control (p = 0.562), bronchial hyperresponsiveness (p = 0.082); or severity of acute bronchoconstriction (p = 0.749). Conclusions: A significant proportion of asthma patients have a poor perception of dyspnea. The factors related to the inability of these patients to identify changes in pulmonary function have not yet been well defined. In order to reduce asthma-related morbidity and mortality, it is essential that this group of patients be identified and counseled.

Keywords: Asthma; Dyspnea; Airway obstruction.

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.

Background: The methacholine challenge test is commonly used to evaluate bronchial responsiveness in diagnosis and follow-up of asthmatic patients. Objective: To investigate late effects of methacholine challenge on induced sputum. Methods: Ten non-smoker patients with mild or moderate stable asthma were recruited. At 12:00 p.m., patients were randomly assigned to inhale either methacholine (challenge) or physiologic saline. At 6:00 p.m., sputum induction was performed. On the second visit, one week apart, patients completed their participation in the study by undergoing another inhalation and sputum induction. Results: After methacholine, 8.6 ± 9 g of sputum were expectorated with 8.6 ± 6 million cells, 78 ± 10% were viable, and 6.8 ± 7% eosinophils. These data were not different from results obtained after saline: sputum amount = 7.6 ± 6 g, total cell count = 12.4 ± 12 million, viability = 82 ± 10%, and eosinophils = 6.6 ± 9%. Expiratory flow (PF) peak fall during sputum induction was not different: 21.4 ± 12% after methacholine and 18.4 ± 15% after saline. The PF fall observed during induction correlated with the amount of expectorated sputum (p = 0.018) and eosinophil relative number (p = 0.003). No other significant correlation between lung function measurements and sputum characteristics was found. Conclusion: A methacholine challenge carried out six hours before sputum induction does not significantly alter the cellular constituents or amount of sputum.

Keywords: Asthma. Methacholine chloride. Bronchial provocation tests.

Objective: To determine the proportion of asthma patients with poor perception of asthma control and to evaluate the characteristics of this subgroup. Methods: A cross-sectional study in which consecutive outpatients (over the age of 12) with mild, moderate, or severe asthma were selected. The patients underwent clinical examination, and pulmonary function tests, as well as being assessed for depression and perception of asthma control. The degree of concordance between patients and physicians regarding the perception of asthma control was determined. Patients with good perception of asthma control were compared, in terms of characteristics, with those presenting poor perception. Results: The degree of concordance between patients and physicians regarding the perception of asthma control was low (kappa index = 0.5). Of the 289 patients included, 66 (23%) presented poor perception of asthma control. The preliminary univariate analysis revealed that the patients with poor perception of asthma control were older, had a lower income, and presented a lower degree of asthma severity. Those factors did not change in the multivariate analysis. There were no differences between the groups in terms of gender, frequency of having literate patients, duration of asthma symptoms, having been diagnosed with rhinitis, frequency of depression, pulmonary function, or treatment compliance. Conclusions: The incidence of poor perception of asthma control in asthma patients is high, especially in elderly patients with lower income and a lower degree of asthma severity.

Keywords: Asthma; Signs and symptoms; Asthma/therapy.

Objective: To evaluate the perception of disease severity in patients with cystic fibrosis (CF), investigating its relationship with clinical score, radiographic score, respiratory function tests, adherence to treatment and perception of self-care practices. Methods: Prospective, cross-sectional study involving CF patients treated in a program for adults with CF. The perception of disease severity, adherence to treatment and reported self-care practices were evaluated by means of questionnaires. Clinical data, Shwachman-Kulczycki clinical score, Brasfield radiographic score and spirometry were obtained for all of the patients. Results: Of the 38 patients studied, 3 (7.9%) patients rated their perception of health status as well below average; 5 (13.2%), as below average; 15 (39.5%), as average; 10 (26.3%), as above average; and 5 (13.2%), as well above average. The perception of disease severity correlated significantly with clinical score (r = 0.43, p = 0.007), FVC (r = 0.34, p = 0.034), FEV1 (r = 0.38, p = 0.019) and self-care practices (r = 0.33, p = 0.044), but not with degree of adherence (r = -0.03, p = 0.842) and radiographic score (r = 0.33, p = 0.51). Conclusions: The perception of disease severity correlated with objective measurements of disease severity (clinical score and respiratory function tests) and with reported self-care practices, but not with adherence to treatment.

Keywords: Severity of illness index; Cystic fibrosis; Patient compliance; Respiratory function tests.

Objective: Few studies have evaluated the variability of the perception of dyspnea in healthy subjects. The objective of this study was to evaluate the variability of the perception of dyspnea in healthy subjects during breathing against increasing inspiratory resistive loads, as well as to assess the association between the level of perception of dyspnea and the level of physical activity. Methods: This was a cross-sectional study involving healthy individuals 16 years of age or older. Subjects underwent inspiratory resistive loading testing, in which the level of perception of dyspnea was quantified with the modified Borg scale. We also determined body mass indices (BMIs), assessed maximal respiratory pressures, performed pulmonary function tests, applied the international physical activity questionnaire (IPAQ)-long form, and conducted six-minute walk tests (6MWTs). The level of perception of dyspnea was classified as low (Borg score < 2), intermediate (Borg score, 2-5), or high (Borg score > 5). Results: We included 48 healthy subjects in the study. Forty-two subjects completed the test up to a load of 46.7 cmH2O/L/s. The level of perception of dyspnea was classified as low, intermediate, and high in 13, 19, and 10 subjects, respectively. The level of perception of dyspnea was not significantly associated with age, gender, BMI, IPAQ-long form score, maximal respiratory pressures, or pulmonary function test results. Conclusions: The scores for perceived dyspnea induced by inspiratory resistive loading in healthy subjects presented wide variability. The perception of dyspnea was classified as low in 31% of the subjects, intermediate in 45%, and high in 24%. There was no association between the level of perception of dyspnea and the level of physical activity (IPAQ or six-minute walk distance).

Keywords: Dyspnea; Respiratory function tests; Exercise test.

Pulmonary thromboembolism and exacerbation of chronic obstructive pulmonary disease are common conditions. Chronic obstructive pulmonary disease is a clinical risk factor for pulmonary thromboembolism. The presentation of acute pulmonary thromboembolism and acute exacerbation of chronic obstructive pulmonary disease often mimic each other so closely that they cannot be distinguished clinically. The structural abnormalities of the lungs in chronic obstructive pulmonary disease make also difficult to interpret the results of noninvasive tests like ventilation-perfusion lung scans. Therefore, diagnosing acute pulmonary thromboembolism in patients with underlying chronic obstructive pulmonary disease is a challenging task. In order to update knowledge of the subject and offer suggestions regarding conduct, we evaluated various studies addressing this theme, including case reports and case series. In addition, we reviewed diagnostic approaches to acute pulmonary thromboembolism, and we reflect upon that topic. The clinical probability of pulmonary thromboembolism concomitant to chronic obstructive pulmonary disease is typically intermediate, as is positivity on the ventilation-perfusion lung scan. Diagnostic algorithms should take that into consideration.

Keywords: Pulmonary disease, chronic obstructive/complications; Pulmonary embolism/diagnosis; Pulmonary embolism/epidemiology; Ventilation-perfusion ratio

Objective: To evaluate the impact of asthma, by gender, in a population sample of asthma patients in Brazil. Methods: We conducted face-to-face interviews with 400 subjects (> 12 years of age) included in a national probability telephone sample of asthma patients in the Brazilian state capitals of São Paulo, Rio de Janeiro, Curitiba, and Salvador. Each of those 400 subjects completed a 53-item questionnaire that addressed five asthma domains: symptoms; impact of asthma on quality of life; perception of asthma control; exacerbations; and treatment/medication. Results: Of the 400 patients interviewed, 272 (68%) were female. In relation to respiratory symptoms, the proportion of women reporting extremely bothersome symptoms (cough with sputum, tightness in the chest, cough/shortness of breath/tightness in the chest during exercise, nocturnal shortness of breath, and nocturnal cough) was greater than was that of men. Daytime symptoms, such as cough, shortness of breath, wheezing, and tightness in the chest, were more common among women than among men. Women also more often reported that their asthma interfered with normal physical exertion, social activities, sleep, and life in general. Regarding the impact of asthma on quality of life, the proportion of subjects who reported that asthma caused them to feel that they had no control over their lives and affected the way that they felt about themselves was also greater among women than among men. Conclusions: Among women, asthma tends to be more symptomatic, as well as having a more pronounced effect on activities of daily living and on quality of life.

Keywords: Asthma/diagnosis; Asthma/prevention & control; Quality of life.

Objective: To evaluate respiratory muscle strength and six-minute walk test (6MWT) variables in patients with uncontrolled severe asthma (UCSA). Methods: This was a cross-sectional study involving UCSA patients followed at a university hospital. The patients underwent 6MWT, spirometry, and measurements of respiratory muscle strength, as well as completing the Asthma Control Test (ACT). The Mann-Whitney test was used in order to analyze 6MWT variables, whereas the Kruskal-Wallis test was used to determine whether there was an association between the use of oral corticosteroids and respiratory muscle strength. Results: We included 25 patients. Mean FEV1 was 58.8  21.8% of predicted, and mean ACT score was 14.0  3.9 points. No significant difference was found between the median six-minute walk distance recorded for the UCSA patients and that predicted for healthy Brazilians (512 m and 534 m, respectively; p = 0.14). During the 6MWT, there was no significant drop in SpO2. Mean MIP and MEP were normal (72.9  15.2% and 67.6  22.2%, respectively). Comparing the patients treated with at least four courses of oral corticosteroids per year and those treated with three or fewer, we found no significant differences in MIP (p = 0.15) or MEP (p = 0.45). Conclusions: Our findings suggest that UCSA patients are similar to normal subjects in terms of 6MWT variables and respiratory muscle strength. The use of oral corticosteroids has no apparent impact on respiratory muscle strength.

The authors present a 62-year-old male patient who had pulmonary nocardiosis with poor evolution. He also presented mental confusion, septic shock and a significant leukocytosis. Poor evolution happened even when sulfamethoxazole + trimethoprim replaced by ceftriaxone + clindamycin as an antibiotic therapy were used. Diagnostic methods, epidemiology and therapy of this infection are discussed and revised. The authors emphasize the importance of an early diagnosis, isolation in culture, and antibiogram examination of Nocardia ssp samples for therapeutic adapting.

Keywords: Pneumonia. Nocardia.

Objective: To characterize a population of patients with bronchiectasis, correlating clinical, radiological, and functional aspects with the severity of dyspnea. Methods: This was a cross-sectional study involving adult patients with HRCT-confirmed bronchiectasis, categorized according to the severity of dyspnea (as being mildly or severely symptomatic, on the basis of the modified Medical Research Council scale). We correlated the severity of dyspnea with clinical parameters, functional parameters (spirometry values, lung volumes, and DLCO), and CT parameters. Results: We evaluated 114 patients, 47 (41%) of whom were men. The median age (interquartile range) was 42 years (30-55 years). The most common form was idiopathic bronchiectasis. Of the 114 patients, 20 (17.5%) were colonized with Pseudomonas aeruginosa and 59 (51.8%) were under continuous treatment with macrolides. When we applied the Exacerbation in the previous year, FEV1, Age, Colonization, Extension, and Dyspnea score, the severity of dyspnea was categorized as moderate in 54 patients (47.4%), whereas it was categorized as mild in 50 (43.9%) when we applied the Bronchiectasis Severity Index. The most common lung function pattern was one of obstruction, seen in 95 patients (83.3%), and air trapping was seen in 77 patients (68.7%). The prevalence of an obstructive pattern on spirometry was higher among the patients with dyspnea that was more severe, and most functional parameters showed reasonable accuracy in discriminating between levels of dyspnea severity. Conclusions: Patients with bronchiectasis and dyspnea that was more severe had greater functional impairment. The measurement of lung volumes complemented the spirometry data. Because bronchiectasis is a complex, heterogeneous condition, a single variable does not seem to be sufficient to provide an overall characterization of the clinical condition.

Keywords: Bronchiectasis; Dyspnea; Respiratory function tests; Multidetector computed tomography; Plethysmography.

Objective: There is an indirect relationship between airway obstruction in asthma and the intensity of breathlessness (dyspnea). A word labeled visual analog dyspnea scale with a 0-3 score has been widely used for the assessment of the degree of bronchoconstriction, although the perception of such obstruction varies considerably. The objective of this study was to determine whether children and adolescents are able to perceive acute exercise-induced bronchoconstriction (EIB), as well as to measure the discriminatory power of a word labeled visual analog dyspnea scale in relation to the intensity of the EIB. Methods: A cross-sectional study involving 134 children and adolescents with asthma and submitted to a six-minute steady-state exercise test on a cycle ergometer. The intensity of dyspnea was determined using a word labeled visual analog dyspnea scale prior to each determination of FEV1. The scale is scored from 0 to 3, with a logical sequence of pictures, ranging from "no symptoms" to "severe dyspnea". Variables were determined at baseline, as well as at 5, 10, and 20 min after the exercise test. The accuracy of the dyspnea scale in identifying the degree of EIB was determined by means of ROC curves for the post-exercise fall in FEV1, using cut-off points of 10%, 20%, 30%, and 40%. Results: Of the patients selected, 111 finished the study, and 52 (46.8%) presented with EIB. The area under the ROC curve increased in direct proportion to increases in the degree of bronchoconstriction. Conclusions: Among children and adolescents with asthma, the accuracy of this dyspnea scale improves as the post-exercise percentage fall in FEV1 increases. However, the predictive value of the scale is suboptimal when the percentage fall in FEV1 is lower.

Keywords: Asthma; Asthma, exercise-induced; Dyspnea.

Objective: To develop a set of descriptive terms applied to the sensation of dyspnea (dyspnea descriptors) for use in Brazil and to investigate the usefulness of these descriptors in four distinct clinical conditions that can be accompanied by dyspnea. Methods: We collected 111 dyspnea descriptors from 67 patients and 10 health professionals. These descriptors were analyzed and reduced to 15 based on their frequency of use, similarity of meaning, and potential pathophysiological value. Those 15 descriptors were applied in 50 asthma patients, 50 COPD patients, 30 patients with heart failure, and 50 patients with class II or III obesity. The three best descriptors, as selected by the patients, were studied by cluster analysis. Potential associations between the identified clusters and the four clinical conditions were also investigated. Results: The use of this set of descriptors led to a solution with seven clusters, designated sufoco (suffocating), aperto (tight), rápido (rapid), fadiga (fatigue), abafado (stuffy), trabalho/inspiração (work/inhalation), and falta de ar (shortness of breath). Overlapping of descriptors was quite common among the patients, regardless of their clinical condition. Asthma was significantly associated with the sufoco and trabalho/inspiração clusters, whereas COPD and heart failure were associated with the sufoco, trabalho/inspiração, and falta de ar clusters. Obesity was associated only with the falta de ar cluster. Conclusions: In Brazil, patients who are accustomed to perceiving dyspnea employ various descriptors in order to describe the symptom, and these descriptors can be grouped into similar clusters. In our study sample, such clusters showed no usefulness in differentiating among the four clinical conditions evaluated.

Keywords: Dyspnea; Pulmonary disease, chronic obstructive; Asthma; Heart failure.

Objective: To identify the predictive factors of oxygen desaturation during the six-minute walk test (6MWT) in patients with cystic fibrosis (CF). Methods: Prospective cross-sectional study involving clinically stable patients with CF aged ≥ 10 years. The patients were submitted to nutritional evaluations, oral glucose tolerance tests, pulmonary function tests, chest X-rays and 6MWTs. Results: The study included 88 patients (43 females and 45 males; mean age, 19.9 ± 7.2 years; mean FEV1, 65.4 ± 28.4%). We observed oxygen desaturation in 13 patients (OD+ group) and no oxygen desaturation in 75 (OD− group). In comparison with OD− group patients, OD+ group patients presented higher mean age (p = 0.004), worse clinical score (p < 0.001), worse radiological score (p < 0.001), higher incidence of glucose intolerance (p = 0.004), lower incidence of methicillin-sensitive Staphylococcus aureus infection (p < 0.001), higher incidence of methicillin-resistant S. aureus infection (p = 0.016), higher incidence of Pseudomonas aeruginosa infection (p = 0.008), lower mean resting SpO2 (p < 0.001) and lower mean FEV1 (p < 0.001). In the logistic regression analysis, oxygen desaturation during the 6MWT correlated with resting SpO2 (OR = 0.305, p < 0.001) and FEV1 (OR = 0.882, p = 0.025). The parameters maximizing the predictive value for oxygen desaturation were resting SpO2 < 96% and FEV1 < 40%. In this sample, 15% of the patients with CF aged ≥ 10 years presented oxygen desaturation during the 6MWT. Conclusions: Resting SpO2 < 96% and FEV1 < 40% can predict oxygen desaturation during the 6MWT.

Keywords: Cystic fibrosis; Respiratory function tests; Exercise tolerance.

Objective: To evaluate the responsiveness of the six-minute step test (6MST) to an aerobic physical training program (PTP) and to determine the efficacy of the PTP regarding spirometric variables during the 6MST, as well as physical performance, sensation of dyspnea, and SpO2 during the 6MST and the six-minute walk test (6MWT), in patients with COPD. Methods: This was a controlled, prospective randomized study involving patients clinically diagnosed with COPD, with an FEV1/FVC ratio < 70%, and having been clinically stable in the last two months. The patients were randomized to undergo a PTP on a treadmill, three times a week, for six weeks (PTP group) or not (control group). Histories were taken from all of the patients, who received regular respiratory therapy during the study period, undergoing physical examination and spirometry before and after bronchodilator use; incremental symptom-limited cardiopulmonary exercise testing; the 6MST; and the 6MWT. Results: Of the 36 patients that completed the study, 21 and 15 were in the PTP and control groups, respectively. In the PTP group, there was a significant increase in the number of steps climbed during the 6MST and in the six-minute walk distance (in m and % of predicted), as well as a significant decrease in the sensation of dyspnea during the 6MWT. Conclusions: The 6MST showed responsiveness to the PTP. However, the 6MWT appears to be more responsive to the PTP proposed.

Keywords: Exercise test; Exercise; Pulmonary disease, chronic obstructive.

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.

To describe the intra-rater and inter-rater reliability of the Brazilian Portuguese version of the fatigue severity scale (FSS) in patients with COPD and to identify the presence of its association with parameters of pulmonary function, dyspnea, and functional capacity. Methods: This was an observational cross-sectional study involving 50 patients with COPD, who completed the FSS in interviews with two researchers in two visits. The FSS scores were correlated with those of the Medical Research Council (MRC) scale, as well as with FEV1, FVC, and six-minute walk distance (6MWD). Results: The mean age of the patients was 69.4 ± 8.23 years, whereas the mean FEV1 was 46.5 ± 20.4% of the predicted value. The scale was reliable, with an intraclass correlation coefficient of 0.90 (95% CI, 0.81-0.94; p < 0.01). The FSS scores showed significant correlations with those of MRC scale (r = 0.70; p < 0.01), as well as with 6MWD (r = −0.77; p < 0.01), FEV1 (r = −0.38; p < 0.01), FVC (r = −0.35; p < 0.01), and stage of the disease in accordance with the Global Initiative for Chronic Obstructive Lung Disease criteria (r = 0.37; p < 0.01). Conclusions: The Brazilian Portuguese version of the FSS proved reliable for use in COPD patients in Brazil and showed significant correlations with sensation of dyspnea, functional capacity, pulmonary function, and stage of the disease.

Keywords: Fatigue; Pulmonary disease, chronic obstructive; Reproducibility of results; Validation studies.