Objective: To evaluate, using pulmonary function tests, the effectiveness of formoterol as a bronchodilator at 30 min after its administration in patients with poorly reversible COPD. Methods: A prospective study including 40 COPD patients not responding to the short-acting bronchodilator used in the spirometric test-variation of less than 200 mL and less than 7% of predicted in forced expiratory volume in one second (FEV1). All patients were classified as having stage II, III, or IV COPD (Brazilian Thoracic Society/Global Initiative for Chronic Obstructive Lung Disease) and presented FEV1 ≤ 70% of predicted value. The patients were randomized into two groups of 20, with similar clinical characteristics, receiving, via a dry powder inhaler, either formoterol or a placebo. The pulmonary function testing (plethysmography) was repeated at 30 min after formoterol or placebo administration. Results: In the formoterol group, the mean values obtained for FEV1, inspiratory capacity, and forced vital capacity were significantly greater than those obtained in the placebo group (p = 0.00065, p = 0.05, and p = 0.017, respectively), whereas that obtained for airway resistance was significantly lower (p = 0.010). Less pronounced differences were observed for residual volume, vital capacity and specific airway conductance, which were lower, higher and higher, respectively, in the formoterol group. Conclusions: In COPD patients not responding to the short-acting bronchodilator used in the spirometric test, formoterol promoted significant improvement in lung function at 30 min after of administration. Further studies are required to confirm whether formoterol can also be used as a medication for immediate relief of symptoms in COPD.

Keywords: Chronic obstructive pulmonary disease; Respiratory function tests; Bronchodilator agents.

Objective: Pulmonary rehabilitation (PR) improves exercise capacity in most but not all COPD patients. The factors associated with treatment success and the role of chest wall mechanics remain unclear. We investigated the impact of PR on exercise performance in COPD with severe hyperinflation. Methods: We evaluated 22 COPD patients (age, 66 ± 7 years; FEV1 = 37.1 ± 11.8% of predicted) who underwent eight weeks of aerobic exercise and strength training. Before and after PR, each patient also performed a six-minute walk test and an incremental cycle ergometer test. During the latter, we measured chest wall volumes (total and compartmental, by optoelectronic plethysmography) and determined maximal workloads. Results: We observed significant differences between the pre- and post-PR means for six-minute walk distance (305 ± 78 vs. 330 ± 96 m, p < 0.001) and maximal workload (33 ± 21 vs. 39 ± 20 W; p = 0.02). At equivalent workload settings, PR led to lower oxygen consumption, carbon dioxide production (VCO2), and minute ventilation. The inspiratory (operating) rib cage volume decreased significantly after PR. There were 6 patients in whom PR did not increase the maximal workload. After PR, those patients showed no significant decrease in VCO2 during exercise, had higher end-expiratory chest wall volumes with a more rapid shallow breathing pattern, and continued to experience symptomatic leg fatigue. Conclusions: In severe COPD, PR appears to improve oxygen consumption and reduce VCO2, with a commensurate decrease in respiratory drive, changes reflected in the operating chest wall volumes. Patients with severe post-exercise hyperinflation and leg fatigue might be unable to improve their maximal performance despite completing a PR program.

Keywords: Pulmonary disease, chronic obstructive/rehabilitation; Exercise therapy; Respiratory therapy.

Objective: Making the differential diagnosis between asthma and chronic obstructive pulmonary disease (COPD) based on the response to inhaled bronchodilators by means of spirometry is controversial.The objective of this study was to identify the most useful spirometric variables in order to distinguish between asthma and COPD. Methods: Retrospective study conducted from April of 2004 to January of 2006, comparing the spirometric parameters of 103 nonsmoking patients with asthma to those of 108 patients with COPD who were smokers for more than 10 pack-years. All of the patients included in the study were older than 40 and presented stable disease at the time of the test. Results: Initial forced expiratory volume in one second (FEV1) was the same in the two groups (pre-bronchodilator FEV1 = 51%). However, patients with COPD were older (66 ± 9 years vs. 59 ± 11 years, p < 0.001) and more frequently male (73% vs. 27%, p < 0,001).After the use of the bronchodilator, the median absolute difference in FEV1 was 0.25 L (range, −0.09 to 1.13 L) in patients with asthma and 0.09 L (range, −0.1 to 0.73 L) in those with COPD (p < 0.001).The highest sensitivity (55%), specificity (91%) and likelihood ratio (6.1) for asthma diagnosis was obtained when the percentage increase in postbronchodilator FEV1 in relation to the predicted FEV1 (Δ%predFEV1) was equal to or greater than 10%.Isolated significant increases in forced vital capacity were more common in patients with COPD. Conclusions: In patients over the age of 40 and presenting obstructive lung disease, a Δ%predFEV1 ≥ 10% is the best spirometric parameter to distinguish asthma from COPD.

Keywords: Spirometry; Respiratory function tests; Lung diseases, obstructive.

Objective: To assess the frequency of variation in forced expiratory volume in one second after bronchodilator use in a sample of patients with chronic obstructive pulmonary disease, correlating such variation with clinical and demographic variables and evaluating the frequency of response presented in forced vital capacity, slow vital capacity, inspiratory capacity, residual volume, airway resistance and specific airway conductance. Methods: A total of 64 patients with chronic obstructive pulmonary disease were submitted to whole body plethysmography, and reversibility of bronchoconstriction after the administration 400 µg of fenoterol was quantified. Results: A response in forced expiratory volume in one second was observed in 31% of the patients. Excluding patients presenting a response in forced expiratory volume in one second, 5% presented responses in 5 of the other 6 parameters, 10% presented responses in 4 parameters, 17.5% in 3 parameters, 27.5% in 2 parameters, and 25% in only 1 parameter. Conclusion: When included in the evaluation of bronchodilator response together with forced expiratory volume in one second, static lung volumes, airway resistance and airway conductance allowed a broader evaluation of those patients presenting a functional pharmacodynamic response. These results are in accordance with the observation that bronchodilator use provides clinical improvement and relief of dyspnea to many patients with chronic obstructive pulmonary disease, even to those in whom such treatment leads to no improvement in forced expiratory volume in one second.

Keywords: Pulmonary disease, chronic obstructive/drug therapy; Bronchodilator agents/therapeutic use; Airway resistance/drug effects; Respiratory function tests; Vital capacity; Forced expiratory volume

Chronic obstructive pulmonary disease is progressive and is characterized by abnormal inflammation of the lungs in response to inhalation of noxious particles or toxic gases, especially cigarette smoke. Although this infirmity primarily affects the lungs, diverse extrapulmonary manifestations have been described. The likely mechanisms involved in the local and systemic inflammation seen in this disease include an increase in the number of inflammatory cells (resulting in abnormal production of inflammatory cytokines) and an imbalance between the formation of reactive oxygen species and antioxidant capacity (leading to oxidative stress). Weakened physical condition secondary to airflow limitation can also lead to the development of altered muscle function. Chronic obstructive pulmonary disease presents diverse systemic effects including nutritional depletion and musculoskeletal dysfunction (causing a reduction in exercise tolerance), as well as other effects related to the comorbidities generally observed in these patients. These manifestations have been correlated with survival and overall health status in chronic obstructive pulmonary disease patients. In view of these facts, the aim of this review was to discuss findings in the literature related to the systemic manifestations of chronic obstructive pulmonary disease, emphasizing the role played by systemic inflammation and evaluating various therapeutic strategies.

Keywords: Pulmonary disease, chronic obstructive/complications; Nutritional status; Exercise tolerance;

Objective: To quantify elastic fibers (EFs) and smooth muscle (SM) cells, as well as CD4+ and CD8+ T lymphocytes, in stable chronic obstructive pulmonary disease (COPD). Methods: Surgical specimens were obtained from 15 COPD patients, 18 smokers without airflow limitation, and 14 nonsmokers. Histological and immunohistochemical methods were employed in order to quantify EFs, SM cells, CD4+ T cells, and CD8+ T cells. Results: There was no significant difference in EF numbers among the three groups (p > 0.05). The number of EFs per unit area of lung tissue (mm2) and the percentage of EFs in the lung tissue were similar among the three groups. The numbers of SM cells were found to be higher in the COPD patients than in the smokers (p = 0.003) or in the nonsmokers (p = 0.009). There was a tendency toward an increase in CD8+ T-cell counts in the COPD patients. In specimens collected from the COPD patients, CD4+ T-cell counts were lower than in those collected from the smokers (p = 0.015) or from the nonsmokers (p = 0.003). There was a weak correlation between CD4+ T-cell count and the ratio of forced expiratory volume in one second to forced vital capacity (r2 = 0.003). Conclusions: The EF counts were similar among the three groups. Hypertrophy/hyperplasia of airway wall SM cells was found in the COPD patients and in the smokers, indicating that airway remodeling occurs in smokers. The CD4/CD8 ratio was lower in the COPD patients.

Keywords: Pulmonary disease, chronic obstructive; CD4 Lymphocyte Count; Elastic tissue; Muscle, smooth.

Long-acting b2-agonists can produce the same level of bronchodilation as anticholinergic drugs in patients with COPD, but due to their lipophilicity, the action persists for 12 h after inhalation. Comparative studies between salmeterol and formoterol demonstrate an equivalent potency of salmeterol 50 mcg and formoterol 24 or 12 mcg when administered respectively by a metered dose inhaler or a turbuhaler. One must consider the inhaler in order to establish the equivalent potency between these two agents. Patients with COPD and associated cardiac diseases can use the long-acting b2-agonists safely. In this particular high-risk group of patients, salmeterol, a partial agonist, is considered safer than formoterol. A reassessment of the bronchodilator therapy in COPD might be considered. Tiotropium bromide is a new anticholinergic drug, the action of which prolongs for more than 1-3 days. It is the most promising new bronchodilator for COPD patients.

Keywords: COPD, long-acting b2-agonists, bronchodilators

Chronic obstructive pulmonary disease is a prevalent condition and is currently the forth leading cause of mortality in the US. The prevalence of respiratory disturbance during sleep, or overlap syndrome as it was commonly known in the past, is still undetermined as conflicting reports have been published. Because of the adverse effects of sleep-related respiratory impairment in patients with underlying pulmonary disease, this condition deserves further investigation. In this report, we will briefly discuss the mechanisms involved in generating respiratory disturbance during sleep in Chronic Obstructive Pulmonary Disease and will guide the reader into distinguishing those patients who would benefit from a more detailed sleep evaluation, discussing management issues and treatment options.

Keywords: Key words: COPD. Sleep disorder breathing. Sleep apnea. Hypoxemia. Hypoventilation

Background: Chronic obstructive pulmonary disease is detrimental to lung mechanics and peripheral muscles. The physical programs developed for this condition are usually targeted to an improvement on aerobics capacity. Programs that approach specifically the changes in thoracic mobility and thoracic muscles are rare. Objective: To assess the effects of a physical exercise program designed to increase chest wall mobility on functional and psychosocial capacity in moderate to severe chronic obstructive pulmonary disease patients. Methods: Thirty patients with moderate to severe chronic obstructive pulmonary disease were studied. They were randomized to 2 groups: control group (CG) and treated group (TG). The CG was submitted to an educational program and the TG was submitted to an educational program plus a physical exercise program aiming to increase chest wall mobility. Variables included spirometry, thoracic mobility, quality of life, anxiety and depression levels and a six minute walk test (6MWT). Results: After 2 months of training, only the TG presented improvements on chest wall mobility (from 4.20 ± 0.58 cm to 5.27 ± 0.58 cm; p = 0.05) and 6MWT (from 469.73 ± 31.99 m to 500.60 ± 27.38 m; p = 0.01). It was also observed that the TG presented improvement on the St. George's Respiratory Questionnaire (SGRQ) score, Chronic Respiratory Questionnaire (CRQ), and Beck's depression scale after 2 months of treatment. Pulmonary function did not improve either in the CG or in the TG group. Conclusion: Our results suggest that exercises aimed to the increasing of chest wall mobility improve thoracic mobility, quality of life, submaximal exercise capacity, and reduce dyspnea and depression symptoms in chronic obstructive pulmonary disease patients.

Keywords: COPD. Thoracic mobility. Quality of life. Capacity of exercise. Dyspnea.

Objective: To describe and analyze clinical symptoms and spirometric alterations of patients with chronic obstructive pulmonary disease (COPD) and history of exposure to wood and tobacco smoke. Methods: We retrospectively evaluated data related to 170 patients distributed into 3 groups: 34 exposed only to wood smoke, 59 patients exposed only to tobacco smoke and 77 patients exposed to both. Results: The groups did not differ significantly in terms of age (p = 0.225) or degree of exposure, considering each type of exposure in isolation or in combination (p = 0.164 and p = 0.220, respectively). Females predominated in the group exposed to wood smoke. There were no differences among the groups regarding respiratory symptoms (p > 0.05), and moderate dyspnea predominated in the three groups (p = 0.141). The group exposed to wood smoke presented higher percentages of forced expiratory volume in one second/forced vital capacity ratio and of forced expiratory volume in one second (p < 0.05). Positive results on bronchodilator testing occurred more frequently in the group exposed to tobacco smoke. The percentage of severe and extremely severe obstruction was significantly higher in the group exposed to tobacco smoke (44.1%) than in that exposed to wood smoke (11.8%; p = 0.006). Conclusions: Respiratory symptoms and pulmonary function alterations consistent with COPD were observed in the groups of patients exposed to wood smoke. However, those alterations were not as significant as the alterations observed in the groups exposed to tobacco smoke. This study emphasizes the importance of prospective studies in evaluating the risk of wood-smoke-related COPD in Brazil, as well as the need for preventive measures in this area.

Keywords: Pulmonary disease, chronic obstructive; Smoking; Air pollution, indoor; Smoke.

Objective: The objective of this study was to evaluate the applicability of a modified version of the Saint George's Respiratory Questionnaire. The version evaluated elicits "agree" and "do not agree", rather than "yes" and "no", responses. The intention is to facilitate the comprehension of double-negative questions and to promote better recollection of symptoms by patients by shortening their symptom histories from 12 months to 3 months. Methods: A total of 30 clinically stable patients with chronic obstructive pulmonary disease were evaluated. The Saint George's Respiratory Questionnaire and the modified version of the same were administered 15 days apart. Results: All of the patients presented health-related alterations in their quality of life. Comparing mean scores between the two questionnaires, the greatest difference was seen in the Symptoms domain. No significant differences were found in any of the remaining domains or in the total scores. In a subsequent analysis, significant correlations between the two questionnaires were found in all domains: Symptoms (r = 0.71; p < 0.001); Activity (r = 0.75; p < 0.001); Impact (r = 0.73; p < 0.001) and Total (r = 0.86; p < 0.001). Conclusion: The modified version of the Saint George's Respiratory Questionnaire is as effective as the original in gauging quality of life. However, various symptoms recollection time frames should be investigated in order to determine which would be the best time frame to employ in the analysis.

Keywords: Pulmonary disease, chronic obstructive; Quality of life; Reproducibility of results; Cross-cultural comparison; Questionnaires

We report the case of a patient with chronic obstructive pulmonary disease and bronchiectasis, chronically using corticosteroids, who acquired pulmonary nocardiosis, which presented as multiple cavitated nodules. The principal symptoms were fever, dyspnea and productive cough with purulent sputum. Chest X-ray and computed tomography of the chest revealed nodules, some of which were cavitated, in both lungs. Sputum smear microscopy and culture revealed the presence of Nocardia spp. The patient was treated with imipenem and cilastatin, which produced an excellent clinical response.

Keywords: Pulmonary disease, chronic obstructive; Nocardia infections; Bronchiectasis.

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: Assess the relationship between adherence to long-term oxygen therapy (LTOT) with mortality in patients with chronic obstructive pulmonary disease (COPD) and chronic respiratory failure and their clinical features. Methods: Longitudinal retrospective analysis of 254 patients with COPD and chronic respiratory failure from 2008 to 2016. At baseline, we evaluated the diagnosis, spirometry values, arterial blood gas analysis, blood count, pulse oximetry, body composition and health questionnaires (dyspnea, quality of life, anxiety and depression). For referred adherence analysis to LTOT we included 199 patients, divided according to prescription of oxygen: 12h/day (G1), 15h/day (G2) and 24h/day (G3). The cause of death and dates were studied over the five-year period. Results: In five years we identified 124 deaths (62.3%). No significant difference was found in mortality between the adherence groups (p=0.75) nor did we find differences in the clinical parameters evaluated. LTOT prescription was not associated with mortality (p=0.07). In Cox regression analysis, there was no association between mortality and non-adherence to LTOT (HR: 0.75; IC95%: 0.21-2.70). The risk of mortality was increased in G3 compared with G1 (HR: 7.16; IC 95%: 1.44-35.38) and in those with a higher depression score (HR: 1.35; IC: 1.14-1.59). Conclusion: No association was found between LTOT adherence and mortality in patients with COPD and respiratory failure. There were no clinical differences between the adherence groups.

Keywords: Chronic obstructive pulmonary disease; Oxygen therapy; Cooperation and treatment adherence; Morbidity and mortality indicators.

Objective: To identify the role of bronchodilators in the maximal breath-hold time in patients with obstructive lung disease (OLD). Methods: We conducted a case-control study including patients with OLD and a control group. Spirometric tests were performed prior to and after the use of a bronchodilator, as were breath-hold tests, using an electronic microprocessor and a pneumotachograph as a flow transducer. Respiratory flow curves were displayed in real time on a portable computer. The maximal breath-hold times at end-inspiratory volume and at end-expiratory volume (BHTmaxVEI and BHTmaxVEE, respectively) were determined from the acquired signal. Results: A total of 35 patients with OLD and 16 controls were included. Prior to the use of a bronchodilator, the BHTmaxVEI was significantly lower in the OLD group than in the control group (22.27 ± 11.81 s vs. 31.45 ± 15.73 s; p = 0.025), although there was no significant difference between the two groups in terms of the post-bronchodilator values (24.94 ± 12.89 s vs. 31.67 ± 17.53 s). In contrast, BHTmaxVEE values were significantly lower in the OLD group than in the control group, in the pre- and post-bronchodilator tests (16.88 ± 6.58 s vs. 22.09 ± 7.95 s; p = 0.017; and 21.22 ± 9.37 s vs. 28.53 ± 12.46 s; p = 0.024, respectively). Conclusions: Our results provide additional evidence of the clinical usefulness of the breath-hold test in the assessment of pulmonary function and add to the existing knowledge regarding the role of the bronchodilator in this test.

Keywords: Respiratory function tests; Pulmonary disease, chronic obstructive; Bronchodilator agents; Apnea.

Introduction: The term quality of life has gained increasing importance in the scientific context. This study describes the adaptation of a disease-specific questionnaire developed by Paul Jones et al. in 1991, the St. George's Respiratory Questionnaire (SGRQ), to the Brazilian language and culture. This questionnaire evaluates the quality of life in patients with chronic obstructive pulmonary disease (COPD) and contains three domains (symptoms, activity, and impacts) divided in 76 items. The questionnaire is self-administrated, but it may be read to illiterate persons. Goal: To verify if the St. George's Respiratory Questionnaire is a valid tool to measure quality of life in patients with chronic obstructive pulmonary disease in Brazil. Methods: In order to validate the questionnaire in Brazil, it was initially translated into Portuguese and afterwards a back-translation into English, that was compared to the original version. A final Portuguese version was then written. This final version was, then, answered by 30 clinically stable COPD patients, according to the spirometry and oximetry values. Patients answered the questionnaire twice, within a 15 day interval. The length of time the patients took to answer the questionnaire and their doubts were noted. Wilcoxon test was used for the calculation of r probability between every single question between the two days; interclass correlation ratio was calculated to test the trustworthiness and reliability of the questionnaire. Results: Among the 30 participant patients, 10 were female and 20 were male. Mean age was 65.9 years. Most of the patients were found to be in stage 2 (56.7 %) of COPD, according to the American Thoracic Society classification. The interclass correlation ratio for the total score of the questionnaire was a = 0.79 and Wilcoxon p = 0.2110 (not statistically significant). The mean answering time for the two days of interview was, respectively, 11 minutes and 50 seconds and 10 minutes and 31 seconds. As concerns the doubts about the questions, the patients reported difficulties in answering Sections 4 and 5, each one of these questions written in a negative form. Conclusion: It can be concluded that the Brazilian version of the St. George's Respiratory Questionnaire is a valid and reliable tool to measure quality of life in patients with COPD in Brazil.

Keywords: obstructive lung diseases, questionnaire, quality of life, reproducibility of results, evolution studies

Depression is the most prevalent psychiatric disorder among hospitalized patients. Chronic obstructive pulmonary disease (COPD) is the most common pulmonary disease, responsible for a high incidence of hospitalization. The purpose of this study is to determine the prevalence of major depression in patients hospitalized due to COPD and correlate such depression with PaCO2, PaO2, respiratory infection, degree of functional airflow obstruction, and steroid therapy. Depression was diagnosed according to DSM IV criteria for major depressive disorders, and assessed by the Beck Depression Inventory. The interview, spirometry, and arterial blood gas analysis were performed between the third and the tenth day of hospitalization. The authors made a prospective study of 51 patients, 34 male and 17 female, with a mean age of 61 ± 11 years. Respiratory infection was the most frequent cause of hospital admission. Major depression was present in 26.9% (n = 11) of the patients, and proportionally higher in females (8 vs 3, p = 0.003). PaCO2 was higher in depressive patients than in non-depressive ones (60.1 ± 18.0 vs 45.8 ± 10.0 mmHg, p = 0.004). Other variables did not display significant differences. The authors conclude that major depression is highly prevalent among patients with COPD, specially in hypercapnic individuals and women.

Keywords: Chronic obstructive pulmonary disease. Steroid. Hypercapnia. Hypoxemia. Depression.

Objective: To determine cell profiles, as well as to identify CD4+ and CD8+ lymphocyte subgroups, in induced sputum (IS) and peripheral venous blood (PVB) of patients with chronic obstructive pulmonary disease (COPD). Methods: Total cell counts and counts of individual cell types, including CD4+ and CD8+ T lymphocytes, were determined in the IS and PVB of 85 subjects (38 with COPD without exacerbation, 29 smokers without obstruction and 18 nonsmokers). Mann-Whitney and Spearman non-parametric tests were used in the statistical analysis, and values of p < 0.05 were considered statistically significant. Results: Comparing the IS of subjects with COPD to that of nonsmokers, neutrophil, eosinophil and CD8+ T lymphocyte counts were higher (respectively p = 0.005, p < 0.05 and p < 0.05), whereas the percentage of macrophages was lower (p = 0.003). There were weak linear correlations (r2 < 0.1) between each cell type in IS and forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and FEV1/FVC ratio. Eosinophil and CD8+ T lymphocyte counts were also higher in PVB (p = 0.04 and p = 0.02). Conclusions: In patients with stable COPD, CD8+ T lymphocyte counts were higher in PVB, whereas total leukocyte counts were similar to those of the other two groups analyzed, suggesting systemic inflammatory involvement. The CD8+ T lymphocyte count in blood can be a useful marker of systemic inflammation and can help identify smokers who already present a COPD inflammatory pattern.

Keywords: Sputum; T-lymphocytes; Neutrophils; Macrophages; Eosinophils; Pulmonary disease, chronic obstructive.

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.